Has this been resolved?
It's hard to pinpoint the exact issue since not of us are physically there to troubleshoot.
But if nothing works, try a different computer, if possible, to see if your tablet works on that machine. This way you can at least isolate the issue before buying a new tablet. If the same issue occur on a different machine, then buy a new tablet. If not, then read below Break Line.
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Based on what you said in your video, it sounds like it's most likely a driver issue rather than a broken tablet because you said the tablet works fine, you just can't adjust the play area.
Have you tried restarting? Have your tried re-install the tablet driver?
Since you said it stopped working out of the blue, do you remember doing anything to the computer prior? Like antivirus update, or Windows updated, installed new program, etc.
FYSA, I doubt your antivirus is blocking the driver, but it's possible.
Windows updated/new software installation can sometimes mess up visual c++ library depending on the new software/update.
I hope this helps.