Have you been using any different products in bath?
At that age it's probably just a difficulty adjusting to the transition. He'll grow out of it soon enough, unfortunately it's just a phase that you'll just have to live through and offer more comfort through.
It's very normal, takes a lot of energy to do a bath or swimming. A bottle straight away afterwards helps
My 3 month old has started doing this like he's raging to be coming out 😂 xx