If you have the version of Learning Agents from UE5-Main (eventually coming to UE 5.6), you can run the python process separately from UE, which means you can easily run train.py from VS Code or your favorite python debugger. This makes it 100% easier to debug compared to adding a bunch of prints.
I think it actually works with 5.5 but I kind of forget, we switched the python CLI from the positional arguments to using argparse so 5.6 will be much better. I wish I could help you more with 5.5 but I’m really busy with working on 5.6
Thanks for pushing through these issues though! I know it’s a pain and can get frustrating (for me at least).