I also have the same screen flicker. I have a HP Laptop with AMD graphics. If it helps at all I can post the model number later. I was trying to troubleshoot.
Currently I'm loving Zorin. I've tried out LinuxFX,Ubuntu Mate,and BionicPup before but do to some confusion defaulted back to Windows. But I legit love Zorin and my Linux understanding over the past few days has grown exponentially.