Bo is not eatting pellets

Hi! Some of you might remember me speaking of Bo, my rescued betta. I'm treatting him for tail rott and think he might have other problems but my main concern is getting him to eat. He'll eat thw Omega betta flakes, but not any of the pellets. I have to cut them to get them small enough for him to eat, but he just spits them out, chases after them, spits them out...

Is there anything I can do? He needs to eat the pellets because they're Jungle brand Fungus Eliminator pellets.

Thank you so much in advance for the help.