Betta Fish: My betta is chronically ill / help

Hello this is my boy Pluto! I have him for a year or so now and he has been sick ever since… tried every treatment in the book i could get my hands on. He first had injury from the log followed by fin rot treated him with methylene blue he got better yaaay. After a while the finrot is back with what looks like an ulcer.. i try aquarium salt he gets better yayy …2 weeks the ulcer is back and it’s bloody i panic and buy antibiotics and almond leaves start him immediately on kanaplex he got so much better he started to even show fin regrowth ! But only a month and so after the ulcer is back… started kanaplex again and it is gone only a scar now. But his fin is still deteriorating each day more and more i have no idea what to do anymore. He shows absolutely no signs of illness other than the continuos finloss . His water parameters is good temperature is 27 c. He eats fluval bug bites and shrimp batties as a treat. Loves to play and explore. Help me i don’t know why he keeps having fin loss despite everything i do!