Loading subclassed model from seperate file fails

Question

I train and save a subclassed keras Model in one file, say file A and want to load it in another file B. The problem that I have is that in file A I can save the model and even load the model back in with no problems, but the moment that I try to load the model in a different file (e.g. file B) I get the following error:

ValueError: Could not find matching concrete function to call loaded from the SavedModel. 
Got:
 Positional arguments (1 total):
* [<tf.Tensor 'inputs:0' shape=(?, 4498) dtype=float32>, <tf.Tensor 'inputs_1:0'  
shape=(?, 4) dtype=float32>]
Keyword arguments: {}

Expected these arguments to match one of the following 2 option(s):

Option 1:
  Positional arguments (1 total):
* (TensorSpec(shape=(?, 4498), dtype=tf.float32, name='inputs/0'), 
TensorSpec(shape=(?, 4), dtype=tf.float32, name='inputs/1'))
 Keyword arguments: {}

Option 2:
Positional arguments (1 total):
* (TensorSpec(shape=(?, 4498), dtype=tf.float32, name='input_1'), 
TensorSpec(shape=(?, 4), dtype=tf.float32, name='input_2'))
Keyword arguments: {}

Does anybody have an idea how to fix this? Or what might cause the problem?