I too have a very similar issue. I have tried using buildtak, kapton on glass, glass, glass with pva (purple elemers glue), kapton with glue, using alcohol to clean the build plate, heated and non heated, heated with all variants, non heated with all variants (meaning glue, spray, etc.)
Mind you this is all PLA. Its a hit and miss with this piece of junk flashforge. YET, SAME BRAND kapton, glue, filament EVERYTHING, prints on my prusa i3 with no issuers. Right on kapton without glue, or hairspray or anything.
So I decided to wipe all replicatorg crap out (GOD I HATE REPLICATORG), when I reinstalled now I keep getting error saying firmware.xml cannot be found. this could be because it was run from a read only system, blahj blah blah which its not. I have been using my prusa i3 with no problems using repetier and I love it. this flashforge junk has been giving me problems since the get go.
The flashforge PRO that I am talking about came with all the pulleys BENT. they replaced the aluminum ones with plastic nylon things that they are wobbling right off the press. I'm so irritated I cant see straight.
And you call their tech support and its a 1 man circus. George answers from sales says he has to transfer you to tech support. then George answers again same voice and says tech support can I help you (after being on hold for 30 minutes)
Can someone please help me?? THEY WONT!