Comment by placesalt

I have the same keyboard (MX Keys). I didn't have the flashing-light problem, but the lights nevertheless would constantly turn themselves off, after a very short (~5s?) period of inactivity.

I spent a not inconsiderable amount of time trying to find a fix, including removing an internal cable and putting electrical tape over the top. Nothing worked. The closest I got was keeping the wireless keyboard plugged into its USB-C charger so that the timeout period before shutoff was longer than it was in battery-only mode.

All of which is annoying, because it's not cheap (>$100), and the fix is so stupefyingly simple - an addition of one or two settings in the configuration software. And, yes, countless people have reported this to Logitech and their 'support' consists, at best, of saying "I'll pass this on to The Team".

Never have I been more tempted to go all-in and become a firmware hacker, though the feasibility in time and probability of success are both quite low.