Feather Duster acting strange

I believe feather dusters can drop their crowns for a few reasons, stress due to bad water params or big changes in environment, and I believe they also drop their crowns to spawn but I would imagine if the worm is hanging out of the tube it doesn't sound good.

How old is your tank? Filter feeders can sometimes be tricky because they need sufficient food that is small enough for them to eat in the water column. A lot of times younger tanks don't have this sort of stuff available so I think a lot of times feather dusters die off due to insufficient nutrients.

Do you feed your tank with something it's capable of eating?