is there a specific limit, on how much elements the "propagate masks" feature is working?
I tried the latest build of corona 7 (april 21.) and still get this behaviour, that after a few objects containing the specific material, the mask is appearing again.
Short Testing: issue appeared after 5 Elements (with 2 sides) ... so in general 10 transitions.
Is there some value in rendersettings which has an influence on this number?