Would you please check if in PowerScheduler when you go to report and if you see the pre-commit validation report? If not, we recommend reaching out to the Technical Contact of your district and asking them to install it.
Before committing the schedule did you run the post build reports to see if all the classes were populated correctly?
So much depends on the setup of PowerScheduler. Year and terms, etc in the scenario need to be correct. Check and see if your courses are set to schedule in the correct year.
I am happy to talk you through this to see what may have been missed.