Mtx wings and tails of nine tails fox pet move awkwardly

I just started noticing this not long ago. I put on the annihilator wings, and every 10, sometimes 20 seconds it shifted a bit to the left and back. Not i was watching my ninetails pet, and he has the same issue with his huge tails.

I don't have a recording of it unfortunately. But it should be easy to see when you put on the annihilator wings and wait a bit.