I unplugged the molex connector from the BMS tonight to cut the power to it in hopes it would reset the monitor. Powered the BMS back on but no change in the monitor unfortunately.
If I long press the display to bring the menu up I get a responsive "beep" but the menu doesn't pop up as usual. The monitor doesn't even respond to quick peck on either side of the screen as if toggling between screens either, so I can't check individual cells now.
Really weird since it went from working just fine to this now.