Hello
This issue is really frustrating.
Whenever I copy any character from live to any PTR server, I can’t login because the character is marked as blocked. I do not have any payment issues.
I initially submitted a ticket but I was directed to post my issue on the PTR forums.
Please help!
Thank you 
same issue here, tried a level 60 last week and a level 51 just now after latest update. Both are in Shadowlands.
Have you tried to copy a character that is not in shadowlands?
Yes lower lever toons work ok and just noticed that the ptr does not have the shadowlands banner on it. Maybe they are thinking it is perfect and bug free so don’t need feedback.
I also contacted support and they gave me links about character copy, death knights and demon hunters and recommended to post on US PTR forums. This is a dead end. Great job!
PTR is still in prepatch state so characters that are in the Shadowlands or above level 50 will be locked.