6 month old puppy regression

So our puppy was completely potty trained at 4 months, he could go to other people’s houses and public places and always knew where to go if he needed to potty.

Recently we went on vacation and boarded him for a week and as soon as we got back he’s started to have intermittent accidents. We use a bell for him to ring on the door and he will ring it most times still but once a day he just out right pees on the floor. What is this?

He’s also biting SO much more and so hard. I feel like he used to be so well behaved and we’ve back pedaled a bunch. Wondering if this is due to us boarding him or if there is some type of regression during this time