I've noticed that Sims who live in Britechester don't get to class on time. If I have them live in the other worlds they do just fine - even when the classes are only 5 minutes apart because they come home and then disappear again to class. Not an ideal solution, but it is a work around until they can fix it.
Idk if this will help, but if you put "testingcheats true" on you can shift click the ground and the option to "Teleport Here" will come up. That's what I've been doing for every single Sim that I send to class. When "Go to Class" pops up in their queue I x out of it, and then teleport them to right outside their building. I do the same for classes that are right after each other. If your Sim is already in the process of doing that action a notification will come up that says something like "Are you sure you want your Sim to miss class?". I choose "Yes" and the action goes away, but I can go into their work panel and choose "Go to Class" once I've teleported them. I know it's not really a solution so to speak, but it's a workaround, for me at least. If you don't like having cheats on you can always turn them off afterwards.
