Dog potty training regression after neutering??

So our pup have been amazing before neutering, he has learnt to ring a bell to go to the balcony whenever he needs to go and has done so consistently for months.. there’s only minor marking issue that developed prior to the neutering but that is rare. Day 3 after his surgery he is suddenly so terrible and as if he has lost all of his potty training and I am not sure why. I don’t remember him ever having consistent accidents in one day … in the morning he decided to potty on his bed , after doing really well with his poo outside. Then again midday he rang to go outside, and outside instead of going to the grass he decides to go on the floor between 2 grass patches … then at night he decides to potty again at the replacement bed. I’m so lost on why he does this and what I can do? It’s also not small amounts of pee like UTI or marking, but he emptied out his full bladder. He has been acting normal and even very active post neuter, other than whining for attention a lot more and whining more when left alone in playpen. He does have a slightly larger/slightly redder area on his surgical site but he has been checked by the vet and only told to monitor it as it’s ok for now. Any help appreciated. Thanks!