Appologise in advance for this long post

I have had my male ball python for a little over a year now he is approx 4 yrs old currently weighs 796g
Since I got him over a year ago he has only ever been force fed 2 rat pups he is not the slightest bit interested in food

Understandably he refused to eat recently as he had suffered from scale rot which has now cleared

He was offered a brained gerbil a few wks ago got it half way down and regurged it so have tried the same 2 more times and not even showing an interest

i have tried mice, rats
smaller items ie small mice, small weaner rat

I have tried live feeding with a small mouse and he didnt even show interest in the mouse it got right up to his face and he done nothing

Even heated food up tried strike feeding drop feeding nothing seems to work

My temps are sitting at 89 - 90 on the hot side, kept in a 33L Rub with 2 hides
keep him in a quiet spot
havent been handling him unless needed

If anyone else can give me some advice I would b grateful as I am running out of ideas worry that if he doesnt eat soon i might lose him
apart from him not eating for over a year now he is still active and looks in good health

i am even picking up a female ball python on friday whos ready for breeding was told that might help him come out of this feeding fast

I have another python plus 4 corns 1 boa,1 hognose & 1 yellow anaconda and they all eat every time not often they refuse a feed unless in shed

Thanks