Probably best to get checked then
When Charlie was that age I took him to get his bottom teeth trimmed as they had got really long. He was freaked afterwards for a few days and hid away but eventually came round again. Hopefully nothing will need doing and the vet can just see properly. Toothache in the back teeth can be an issue too and not much to do about that apart from soft food. Assume you’re still putting his regular mix out as well. They still like to pouch and hoard it even if they’re not eating much of it.