I've seen similar problems with my
Central Services Dispatcher, which reassigns garbage trucks and hearses in a way similar to the Overwatch mods, and have had reports of similar problems with TMPE as well.

I've actually seen a few problems with stuck vehicles without T++ and TMPE as well. It currently seems, to me, like the game has become more sensitive to reassigning vehicle targets in different stages than it used to be. This might be more pronounced with modded path finders, possibly because they can be slower than the original and therefore have vehicles in a "waiting for path" state longer.

I'm currently trying to limit reassigning of vehicles for different states to see if that helps with the problems I see without T++, and once I've got a handle on that I'll start using T++ again to see if it helped there as well.

If I fix it in my mod, it's likely that the findings will be usable for the Overwatch mods as well.