Did some investigation and I understood what was going wrong 🤩
On the whiteboard, you have the option to Enable or Disable all the employee led classes, and to select specific lectures/classes that can be taught on this board. Enabling or Disabling all applies a trigger state that enables/disable all the lectures/classes. You can then select classes individually.
The issue is, the enables/disable all trigger is applied again each time you load the lot. So if you disabled all the lectures/classes before selecting the ones you want, all the classes will be disabled again when loading the lot. Because of that, Sims you designated as teachers won't use the whiteboard to autonomously give lectures, and won't use the board to give a lecture when asking to start a class.
I tried to create a workaround with a third state, that is set after applying the disallow all or enable all, that doesn't trigger anything and it made it work like it was intended. Will share that as a mod, but I think the fix here is to trigger enabling/disabling all the lectures/classes only when the interaction to do so is used, and not doing it everytime the lot is loaded 🤗
As we wait for the bug to be fixed, you can grab that here, it solves other issues with classes and lectures (🎒 Fixed Classes & Lectures)
Another issue regarding that, is that if there are other lectures on the lot, Sims will leave to listen to those other lectures that are not led by their hobby class instructor.
I doesn't happen that much for classes where Sims have something to do (like handiness, cooking...) but a lot for classes like charisma where Sims tend not to use objects.
