@legosnowqueen welcome to the thread. We have been going through the same thing. We have just gone back to basics but its been slow. Not sure what to suggest, we are just putting him out regularly, after food, sleep, play etc and lots of praise when he does go. We thought we'd had a perfect day with no accidents and I've just noticed hes wee'd in the crate, possibly when I left him earlier but not sure as he had only just been. Its so frustrating as he was so good from very little.
Others have said it just clicks arundel the 5 month mark, we are pretty much there and he definitely knows where to go and how to tell us but he chooses not to at times. My hope is that we will keep doing what we're doing and in a month or so he will be bigger and won't need to wee so often so will always just go outside. He never poos indoors.