Worst case- perhaps separation anxiety is coming back- they are famous for that. They are awfully attached to people. Mine will follow every family member anywhere especially my Mother at any given moment. He's crate trained too and SOMETIMES he cries in the crate if he's alone.
Or could be something as simple as his sleep cycle is messed up. Mine will go through small cycles where he'd get up a few days in a row early and want to party or whatever then he'll be normal for months..
Mine is technically a rescue and this perhaps the most behaved dog in the universe. He's 3 years old and lazy and quiet and quite affectionate.
rjp