locked WSIT-X RF & SQL affect on FT8 signals


I have used FT8 for for several years with much success with my TS-590SG, but I noticed something today that I never saw before and I need the forum's advice on it. I noticed that I had no WSJT left side dB bar reading in the green - no nothing. I then noticed that I had to have the SQL open (5.5) a little as well as the RF slightly closed (8.5) to even get a green bar? I don't believe this is normal? Shouldn't I be able to closed the SQL and RF completely (10 reading) and still have a green dB bar?  I checked my TS-590S & sound card settings and they all seem good. 

One other note when I reduce the RF gain even slightly, I get a board red line across the MSK144 waterfall?  See below attachment - Blue bar RF at 10 no left side dB green bar.  RF at 9.5 green bar and large red bar in waterfall.
Confused - any help appreciated