Read up on fin rot treatment and added salt to water. Hopefully it will help them, though I think any damage is already done. Was quite hard to see the white telltale signs of fin rot on them because well.. they are white fish, lol.
When we got them they were fairly small, maybe an inch or a bit larger long/high?
Had them for 2-3 months (I think), I can't remember if they always did it, just remember them being harassed by swords a bunch.
Well we got them from a breeder who had bred a TON of them, so it could be a possibility
Don't want do anything like culling them, just want to help their living conditions if possible/needed.
The ones I have are in a well established 90L community tank, so I don't think it's a lack of good bacteria .
Edit, just found this;
I did see them struggling to stay mid-tank, I thought it was just because of missing parts of fins though