I'm also having this issue. I played a puzzle and then it started working I think but I couldn't match with anyone. A couple hours later the same thing happened.
"Cannot create a challenge because you are currently playing" Help?
This just happened to me, too. Still can't find a fix online. Tried talking to Chessica, but that AI is pretty much useless
Same issue, I can also play with bots and puzzles but not games. Restarting/solving puzzles/changing pc or browser didn't fix the issue
I corrected it many weeks ago by rebooting my internet modem btw