All right. Reinstalled and tested. Still not working the way β I think β it should. It could, of course, be me, but if it is then we need better instructions.
I don't have time right now because I am about to go to the airport, but basically, I have it working okay if I set it to Use Global Configuration. Anything else does not work. If I set it to Open, the thread accepts tags but does not keep them when you save. If I put Closed or Prefix, I get the You are using closed system tagging but no tags have been set up, even though I do have tags set up.
I'll keep trying variations on the screenshot I have attached β I have already tried multiple configurations β but so far not succeeding, sorry.