Fix broken tests in main.

[lllAlexanderlll]

What does this PR do?

This PR fixes the broken tests in main by check for fixed_num_batches is not None before comparison

General Changes

• if statement

Breaking Changes

• None

Checklist before submitting final PR

• [X] My PR is minimal and addresses one issue in isolation
• [X] I have merged the latest version of the target branch into this feature branch
• [X] I have reviewed my own code w.r.t. correct implementation, missing type hints, proper documentation, etc.
• [X] I have run a sample config for model training
• [X] I have checked that all tests run through (python tests/tests.py)