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Multi input problem Keras. Expected to see 2 array(s), but instead got the following list of 1 arrays

I have a model that takes two inputs of the same shape (batch_size,512,512,1), and predict two masks each of shape (batch_size,512,512,1).
dataset_input = tf.data.Dataset.zip((dataset_img_A, dataset_img_B))
dataset_output = tf.data.Dataset.zip((seg_A, seg_B))
dataset = tf.data.Dataset.zip((dataset_input, dataset_output))
dataset = dataset.repeat()
dataset = dataset.batch(batch_size, drop_remainder=True)
I'm creating a model like so:
image_inputs_A = layers.Input((512,512,1), batch_size=self.batch_size)
image_inputs_B = layers.Input((512,512,1), batch_size=self.batch_size)
output_A = some_layers(image_inputs_A)
output_B = some_layers(image_inputs_B)
model = models.Model([image_inputs_A, image_inputs_B],[output_A, output_B])
However I'm getting the following error
ValueError: Error when checking model input: the list of Numpy arrays that you are passing to your model is not the size the model expected. Expected to see 2 array(s), but instead got the following list of 1 arrays: [<tf.Tensor 'IteratorGetNext:0' shape=(?, 2, ?, ?, ?) dtype=float32>]...
It seems that its concatenating the inputs to (batch_size,2,512,512,1), instead of listing them as a tuple of two tensors (batch_size,512,512,1 ). Is this the expected behaviour? How can I use multiple inputs without them concatenating?
EDIT:
I have tried to use an layers.Input with shape (batch_size, 2, 512, 512, 1) and then pass through two lambda layers to split the tensor along the second axis, however.. I get the following error
ValueError: Error when checking input: expected input_1 to have 5 dimensions, but got array with shape (None, None, None, None)
EDIT 2:
I've double checked the data im inputing into the model.
INPUT: (512, 512, 1) <dtype: 'float32'> INPUT: (512, 512, 1) <dtype: 'float32'> OUTPUT: (512, 512, 1) <dtype: 'int64'> OUTPUT: (512, 512, 1) <dtype: 'int64'>

SOLVED: Turns out it was an issue with the data augmentation step where tensors where concatenated inputs. Lesson learnt

How to transform tensor with shape (4498,) to (None, 4498)?

I am trying to transform a tensor with shape (4498,) to a tensor with shape (None, 4498). I tried to reshape it, but it gives a tensor with shape (1, 4498). I tried a lot of other ways to transform it, but none of them worked. Any ideas?
print(info_state.get_shape()) #(4498,)
info_state = tf.reshape(info_state, [-1, 4498])
print(info_state.get_shape()) #(1, 4498)

errors with tensorflow reshape and resize layer

I want to reshape and resize an image in the first layers before using Conv2D and other layers. The input will be a flattend array. Here is my code:
#Create flat example image:
img_test = np.zeros((120,160))
img_test_flat = img_test.flatten()
reshape_model = Sequential()
reshape_model.add(tf.keras.layers.InputLayer(input_shape=(img_test_flat.shape)))
reshape_model.add(tf.keras.layers.Reshape((120, 160,1)))
reshape_model.add(tf.keras.layers.experimental.preprocessing.Resizing(28, 28, interpolation='nearest'))
result = reshape_model(img_test_flat)
result.shape
Unfortunately this code results in the error I added down below. What is the issue and how do I correctly reshape and resize the flattend array?
WARNING:tensorflow:Model was constructed with shape (None, 19200) for input Tensor("input_13:0", shape=(None, 19200), dtype=float32), but it was called on an input with incompatible shape (19200,).
InvalidArgumentError: Input to reshape is a tensor with 19200 values, but the requested shape has 368640000 [Op:Reshape]
EDIT:
I tried:
reshape_model = Sequential()
reshape_model.add(tf.keras.layers.InputLayer(input_shape=(None, img_test_flat.shape[0])))
reshape_model.add(tf.keras.layers.Reshape((120, 160,1)))
reshape_model.add(tf.keras.layers.experimental.preprocessing.Resizing(28, 28, interpolation='nearest'))
Which gave me:
WARNING:tensorflow:Model was constructed with shape (None, None, 19200) for input Tensor("input_19:0", shape=(None, None, 19200), dtype=float32), but it was called on an input with incompatible shape (19200,).
EDIT2:
I recieve the input in C++ from a 1D array and pass it with
// Copy value to input buffer (tensor)
for (size_t i = 0; i < fb->len; i++){
model_input->data.i32[i] = (int32_t) (fb->buf[i]);
so what I pass on to the model is a flat array.

Your use of shapes simply doesn't make sense here. The first dimension of your input should be the number of samples. Is it supposed to be 19,200, or 1 sample?
input_shape should omit the number of samples, so if you want 1 sample, input shape should be 19,200. If you have 19,200 samples, shape should be 1.
The reshaping layer also omits the number of samples, so Keras is confused. What exactly are you trying to do?
This seems to be roughly what you're trying to achieve but I would personally resize the image outside of the neural network:
import numpy as np
import tensorflow as tf
img_test = np.zeros((120,160)).astype(np.float32)
img_test_flat = img_test.reshape(1, -1)
reshape_model = tf.keras.Sequential()
reshape_model.add(tf.keras.layers.InputLayer(input_shape=(img_test_flat.shape[1:])))
reshape_model.add(tf.keras.layers.Reshape((120, 160,1)))
reshape_model.add(tf.keras.layers.Lambda(lambda x: tf.image.resize(x, (28, 28))))
result = reshape_model(img_test_flat)
print(result.shape)
TensorShape([1, 28, 28, 1])
Feel free to use the Resizing layer instead of the Lambda layer, I can't use it due to my Tensorflow version.

reshape a matrix from [?, 100] to [batch_size, ?, 100]

I'm building an autoencoder based on RNN. After FC layer, I have to reshape my output to [batch_size, sequence_length, embedding_dimension]. However, my sequence length(timestep) for my decoder is uncertain. What I wish is something work as follow.
outputs = tf.reshape(outputs, [batch_size, None, word_dimension])
Or, is there any other way for me to get the sequence length from the input data which has a shape [batch_size, sequence_length, embedding_dimension].

You can use -1 for the dimension in your reshape operation that you want to be calculated automatically.
For example, here:
x = tf.zeros((100 * 10 *12,))
reshaped = tf.reshape(x, [100, -1, 12])
reshaped will have shape (100, 10, 12)
Or, is there any other way for me to get the sequence length from the input data which has a shape [batch_size, sequence_length, embedding_dimension].
You can use the tf.shape operation to find the shape of a tensor at runtime so if you want sequence_length in a tensor with shape [batch_size, sequence_length, embedding_dimension], you need just call tf.shape(x)[1].
For my example above, calling:
tf.shape(reshaped)[1]
would give an int32 tensor with shape () and value 10

Keras SimpleRNN confusion

...coming from TensorFlow, where pretty much any shape and everything is defined explicitly, I am confused about Keras' API for recurrent models. Getting an Elman network to work in TF was pretty easy, but Keras resists to accept the correct shapes...
For example:
x = k.layers.Input(shape=(2,))
y = k.layers.Dense(10)(x)
m = k.models.Model(x, y)
...works perfectly and according to model.summary() I get an input layer with shape (None, 2), followed by a dense layer with output shape (None, 10). Makes sense since Keras automatically adds the first dimension for batch processing.
However, the following code:
x = k.layers.Input(shape=(2,))
y = k.layers.SimpleRNN(10)(x)
m = k.models.Model(x, y)
raises an exception ValueError: Input 0 is incompatible with layer simple_rnn_1: expected ndim=3, found ndim=2.
It works only if I add another dimension:
x = k.layers.Input(shape=(2,1))
y = k.layers.SimpleRNN(10)(x)
m = k.models.Model(x, y)
...but now, of course, my input would not be (None, 2) anymore.
model.summary():
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
input_1 (InputLayer) (None, 2, 1) 0
_________________________________________________________________
simple_rnn_1 (SimpleRNN) (None, 10) 120
=================================================================
How can I have an input of type batch_size x 2 when I just want to feed vectors with 2 values to the network?
Furthermore, how would I chain RNN cells?
x = k.layers.Input(shape=(2, 1))
h = k.layers.SimpleRNN(10)(x)
y = k.layers.SimpleRNN(10)(h)
m = k.models.Model(x, y)
...raises the same exception with incompatible dim sizes.
This sample here works:
x = k.layers.Input(shape=(2, 1))
h = k.layers.SimpleRNN(10, return_sequences=True)(x)
y = k.layers.SimpleRNN(10)(h)
m = k.models.Model(x, y)
...but then layer h does not output (None, 10) anymore, but (None, 2, 10) since it returns the whole sequence instead of just the "regular" RNN cell output.
Why is this needed at all?
Moreover: where are the states? Do they just default to 1 recurrent state?

The documentation touches on the expected shapes of recurrent components in Keras, let's look at your case:
Any RNN layer in Keras expects a 3D shape (batch_size, timesteps, features). This means you have timeseries data.
The RNN layer then iterates over the second, time dimension of the input using a recurrent cell, the actual recurrent computation.
If you specify return_sequences then you collect the output for every timestep getting another 3D tensor (batch_size, timesteps, units) otherwise you only get the last output which is (batch_size, units).
Now returning to your questions:
You mention vectors but shape=(2,) is a vector so this doesn't work. shape=(2,1) works because now you have 2 vectors of size 1, these shapes exclude batch_size. So to feed vectors of size to you need shape=(how_many_vectors, 2) where the first dimension is the number of vectors you want your RNN to process, the timesteps in this case.
To chain RNN layers you need to feed 3D data because that what RNNs expect. When you specify return_sequences the RNN layer returns output at every timestep so that can be chained to another RNN layer.
States are collection of vectors that a RNN cell uses, LSTM uses 2, GRU has 1 hidden state which is also the output. They default to 0s but can be specified when calling the layer using initial_states=[...] as a list of tensors.
There is already a post about the difference between RNN layers and RNN cells in Keras which might help clarify the situation further.