X-CUBE-AI: Mismatch in presence of batch size

[pignaz]

Hello,
I'm using X-CUBE-AI to implement an ONNX model on a STM32H757I board.
In particular, the ONNX model is a PyTorch model that has been exported using the onnx library offered by the pyTorch framework.

The analysis procedure fails and reports the following error message:

INTERNAL ERROR: Mismatch in presence of batch size: [['H: 40', 'W: 1', 'CH: 6'], (Empty)] vs. [['BATCH: 1', 'CH: 6']]

But the model input have static dimension, and running get_inputs() on the onnx model returns:

NodeArg(name='actual_input_1', type='tensor(float)', shape=[40,1,6])

The model seems to comply with the constraints reported in the STM32CubeAI documentation.  

Can you help me identifying what's wrong with the model?

Thank you!
Andrea