Describe exactly how you are feeding them? Anything beyond gently placing the food at the surface and leaving is too much activity.
It sounds to me like you are scaring them. The spinning around on the bottom and then kicking over is exactly what happens when they get frightened. I see that all too often on a tank transfer.
I wouldn't be turning on lights, changing water, sticking your face up to the glass, putting a hand/baster into the water, etc.
The only other thing as described by someone else's post would be BBS egg capsules, but if they are decapsulated - then that's not the problem.
Here's exactly what I do. When feeding rots or bbs, I use a turkey baster to wash them into a 3oz cup from the strainer is used - trying to use as little rinse water as possible from my sump water. I pour the cup at water level (no splashing) in and leave. When feeding Oto A, I leave one of those floating feeding squares in the aquarium at all times and sprinkle the food into it and leave.
The other thing you do have to do is water changes. I siphon/vacuum the bottom out with a clear rigid tube (clear to not scare them). I drip in via airline tubing over several hours the replacement water - never pour in change water on the fry. I change 30% of the fry water every 3rd day using this method. I also try to time not doing a water change during meta. I skip a change right at the peak of their meta for a 6 day stretch of no water changes. My percs meta right around day 14. Around meta they are very sensitive. BTW - I only use my display water as the replacement water for my clown grow out water - new mix up water only replaces my display.
-John