Your problem may differ from mine, but whenever I've been greeted with the command line in grub the solution has actually been in bios. I'll leave you with my notes, which are a bit snarky after spending a lot of time trying to figure out hot to repair grub, when the solution was 3 clicks in bios:

"Inspiron won't boot

Goes to the grub command prompt

Don't fuck with that thing

Restart, F2 to get into bios

Change boot sequence to start the SSD first, not ubuntu

Reboot, itll do it a couple times, but should boot right into normal grub"

I hope your solution is the same

Maybe click on that lux entity in the dashboard and see if it has been consistently transmitting its data (on the history graph)? I'm pretty sure you'll get this warning if the state reads "unavailable" which could be a reception issue or a dying sensor.

I recently saw this happen to an animation of mine and I think this was the cause