[DU] Professor Changes Almost Every Term

I think this sounds like normal behaviour to me. There are two premade professors for each university - for Britechester it's Jing Fen (Grumpy Professor) and Thomas Jabari (Nice Professor). For Foxbury, the two premade professors are Serena Bhamra (Grumpy Professor) and Lana McKinnon (Nice Professor).

But there are four different professor archetypes - your game will generate the missing professors to be new randoms when it needs those slots filled - each university campus will need a Bro Professor and a Smart Professor position filled. Once each university has all four of those types of professor filled, the game should consistently reuse those for the classes when it needs to. And each class type seems to have a preference - for example classes related to physical fitness skills and health I've seen use the bro professor more often, which is why you might not see the game use the premades for those as they don't match the professor type.

There's always the possiblilty for extras being generated when the existing ones are occupied - for example the game uses a Smart Professor for the Robot Competition at Foxbury, but if the Smart Professor is already walking by on the campus the game might generate an extra to judge the competition because it couldn't summon the existing one. That's just an example of what I've seen the game do while handling NPCs.

I don't see any reason not to have those extra professors be random. I don't need a full staff of premades - having half premade and half random will keep people's saves fresh and full of variety.