LOL, this one got me too!
Glad Alan made it easy to update the HL2 gateware, I ended up doing it three times before I read this post!
I had the info about the 192 kHz bandwidth in my notes, but hadn't read the notes in at least six months.
I kept wondering why the waterfall looked good and there was audio, but no FT8 decodes.
Went back to the 4 RX gateware, then thought of something else to try twice, no result till I tried searching this group!
All's good now, except my poor PCs fan keeps coming on every 15 seconds or so.