My Qi appears to be locked, and I haven't reached the "100 Qi per day" limit. My rank still changes when I win and lose though, it's just my Qi that's locked, so I don't know what's wrong. Is there any way I can fix this?

Nope, it is the same for all players. It is originally meant so you can only win 100 games of tc in official rooms... (So like you win in a blackbelt or qa room, you can only win the tc 100 times before it stops) but there is a limit on the qi too.

So if I play in rooms where I don't get TC I'll get the Qi?

Nope, your qi will stop too.

So when does this lock wear off?

if u reached it u have to wait 24 hours usually. or just the next day. im not sure.

Damn, okay.