Just for kicks you may want to cycle the monitoring button on the fast rack just to make sure it toggles properly.
TH2 in stand alone mode is another thing to try. Also try swapping TH2 patches, since you can insert splitters into chains internally to TH2 as well. If it occurs on several TH2 patches, it would seem the dry signal is coming through the monitoring path on your fast track. A driver re-install may help, but I am not familiar with that unit (or if it has any Win10 issues).