You tank water parameters are bad. You have too much NH4. When BTA's split by themselves, that is a bad sign. When they move around and cannot find a place, that is a bad sign. A floating nem, is a bad sign. I would do a couple of 50% water changes if that is practical.
Checking the level of NH4 is a waste of time since the level that is toxic for anemone is way below anything that can be measured.
In this condition nems tend to float down stream and will wind up in your intakes. Block them off and put a bubbler in your tank opposite of any intakes.
Good luck.