CC 2015 BAD BUGS!
So um, BIG FAT WARNING: If you’re on the Cloud, don’t installed Flash CC 2015 just yet. Dual monitor setups are screwed.
This is what happens
The squiggle is drawing with a mouse. The lines….with a tablet pen on a Cintiq 22HD.
Mine’s is not a unique problem (other people on the internet have reported similar issues…and I’ve encountered an issue like this in Flash CC 2014 too).