Motion 4 right on, masking issues

The idea is 2 lines that is a frame, I want it will showing up and then a picture comes up after suiting in the frame, so I imported the lines from Ai, and the picture in differents groups and use the paint stroke with right on behavior to make it show up. I did it to the first line, but when I did to de second one, the first line was gone when it was playing, and parts of picture that was hidden showed up.
So if anyone can help I really appreciate.