Not an expert but clearly lots of time on my hands.kno4te
Might as well bring the disease expert on for a second opinion before you do anything ?
I’d check the water and make sure ur number are good. Check the appearance of the poop. Also see any aggression from the pbass to the oscars. If water is good then don’t worry. If poop is white and stringy then feed some hex shield. If it’s aggression then you’ll have to separate. Once separated the pbass May beat on each other and need more pbass to offset that. Which means a bigger tank. Check those things and get back to us.