I've found something odd: I hand painted a mask on dynamask for smart material, all good. Immediately after, I added another smart material and it resulted a mess, looked inside to see what was happening and it appears that it pasted that mask i painted before on most layers, even those that don't use hand painted masks…
Sorry for the delay, i could check again, but from what i remember i did accept the mask but it wasn't closed. As an extra info, this appears to be project-dependant, in the sense that its only happening on 2 projects i started the same day, whatever i do on them the masks say open and get pasted on new materials. But…