This has only happened once but after updating v3.11. Tixati is launched with -starthiddenintray.
I checked on Tixati and saw that it wasn't uploading at all, only connected to channels. Then I looked at Transfers and saw the reason. Tixati had only initialized like 100 out of 600 torrents and they all happened to be the idle. The rest of the torrents was stuck at "Scanning 0%" and force check wouldn't help.
I looked at the diagnostics windows and everything was idle. The hash checker's CPU would just from 0ms to a very low number every few couple seconds and that's it. No excessive CPU usage to indicate a busy spin wait. After restart Tixati continued to work fine. I don't know what it was, but I will post again when I witness this.