more for the guys that bought these balls (Homepin brand), it has been brought up on Pinside very recently but couldn't find a announcement on here (AP) that these balls were recalled back in September last year but only from the distributors, so it seems not made public.
the reason I think people need to know is that an aussie recently discovered the balls started to flake and chip apart leaving metal flakes in the game which would damage the playfield and seems more so for games with magnets
So not to rub salt in wounds or rock the boat but it it means damage could be caused to you playfield, so if you have these maybe best to replace with another brand for the moment.