Dan.,
i'll keep it brief as the weekend is soccer pour moi.lol.
well done dan!
the only next step i might suggest is that you and TVI
compare your reaper and biab settings as well as win
recording/playback settings . thus identify any discrepencies in settings. i would love to know why it works fine for one but not other. cos maybe we can help people in the future if this occurs again.

out of curiosity were you running reaps with asio and biab with was drivers ?. due to my vision i couldnt make out from your vid reaps settings under the X.

best
oldmuso

my songs....mixed for good earbuds...(fyi..my vocs on all songs..)
https://soundcloud.com/alfsongs
(90 songs created useing bb/rb)
(lots of tips of mine in pg tips forum.)