FF800 with TCO installed does do weird stuff... but N5.5.6 works flawlessly.
I don't have time to attempt N6 again. I'm waiting for an update.
I'm still faffing about with the best way to sync with the TCO simply because it seems to be there for Asio drivers ONLY.. but if you don't use the video in, there are occasional minor drop outs.
Yesterday I had absolutely NO issues with house WC & LTC into my Mark of the unicorn digital timepiece then sending video out of that into the TCO & the WC output into FF800 WCin.
If I use house video ref on it's own to the timepiece, I sometimes have issues.
This way (for some reason) seems to work so I'm leaving it as is....