White Spots on Montipora Digitata

[SPSjunky]

I have these white spots on my monti and can't figure out what they are. They are also on the plug as seen below. They seem calcified and do not come off easily, recently got the frag, dipped when got it and dipped it again. Seems like more have been popping up on it.

Any thoughts on what they could be and the causation?

 

[MikeyZo]

They look like spiroid worms

 

[PrattysReef]

Look like spirorbid worms to me