When setting media in a layer, modul8 plays that media from the beginning.
In beta14, when switching between media A and B in the same layer, every time you switch to B it flashes the frame from where the playhead last was in media B before seeking to frame 0. This creates a dirty flashing of stale frames when switching between media.
e.g. if switching every 2 seconds, you see A play from frames 0-60, then a flash of B frame 60 followed by B playing from 0 to 60, then a flash of frame 60 of A followed by A playing from 0 to 60 etc