I have run across a similar issue. You could try to change your network a bit and put both pictures in the same array and break them apart in the forward function of your model. So your dummy_input could be shape (1,153,224,224) where channels 151-153 are the “dummy_input1” and 1-150 are “dummy_input2”. You can then reshape within your forward model. This worked for me. Goodluck!