Weird Issue with NPCs

Ugh. I'm super frustrated with my game, and I would love to know if anyone has ever encountered my current problem.

So, I have a teen sim whose parents just passed, and is about to become a YA.  All has been going okay, until suddenly I discovered that this sim cannot interact with any NPC in the world that  he hasn't already met.  I do play with mods, but only a few.  I removed them from the game and continued having problems.

He can interact with objects in the world.

He CAN interact normally with sims he already has a relationship with.

Interacting with this sim seems to be functioning as usual.

He CANNOT interact with sims he hasn't met.  If the sim is far away, the call sim option is the only thing that comes up.  If an unknown sim is nearby, nothing comes up at all.

I tested this with a different playable sim, and had no problems, with or without mods.

I cleared the cache.  I tried to repair the game. 

What am I missing? Is it game over?