Potty Training Plateau

Ive been pretty happy with our progress so far, but I feel like we’ve hit a plateau. When we are at home I’ve just been leaving him without undies or pants for the most part. Bare butt he hasn’t had any accidents. He will announce he has to go potty, then run and sit on his own. But if he has undies on he always pees a little in his undies, then says potty & will go finish. To clarify, in case you have the same first thoughts I did, I have been VERY watchful, he is not peeing first when his undies are off, not even a drop. Also, he is not saying potty, then going before he can get his undies off when they are on, he’s wet, then says potty.

But here is the really confusing part! When we aren’t home, and obviously he has underwear on, he tells me BEFORE he pees! He hasn’t had an accident away from home in well over a week. He’ll say potty & is dry when we get to one. ?!?

Anyone else deal with something similar?