Tyler, the red line is showing where 30dB signal strength is. Like mentioned above, you need better than 40 on a bunch of sats to have a chance of getting FIX mode. Even in an open field with good visibility, I was unable to get the Here+ to move from FLOAT to FIX (other than for short bursts). I plan to try again, but only with better RTK antennas and with better EMI shielding (better isolation from my RFD900x radios.
If you really want to get the Here+ system working, I’d recommend you try better antennas, and maybe try the system with just the PixHawk and Here+ alone (i.e., without the drone and telemetry radios). If you get this “breadboard” PixHawk/Here+ working, then add the radios back, then if that works mount the system back on the drone.