Stefano_Di_Pietro:

This model is running on a Ubuntu 20.10
The Graphic card is a GeForce GTX1060, driver Version: 460.80
CUDA Version: 11.2
cuDNN: 7.6.5


For TF v2.5 the minimum cuDNN version appears to be 8.1
GPU support  |  TensorFlow 4 - do you think this may be causing the issue or are you running your setup with TF v2.4 or lower?
Alternatively, maybe trying v2.5 in a Docker container (as @bhack might recommend) - Docker  |  TensorFlow 1 - can help resolve this issue.