I am experiencing the same problem casting to my TCL/Roku TV.
My PC "sees" my TV and gives me an "allow or deny prompt" message at the bottom of the screen, when I respond with allow, the screen goes blank except the "pear" images stays. and my PC says it was unable to connect. All indications are the TV is receiving the request from the PC but is not connecting.
I see MsAntipodes1 was able to correct their problem by changing their phone settings, but again, my problem is connecting to my PC. I have tried all of the preliminary steps suggested here, are there other steps or settings I should be looking at ? or any other suggestions ?
Thanks,
Bruce