Hmmm that can happen to.
I have had 2 systems with unified logitech units in the same room but never had a problem like that.
Batteries are the issue usually.
Always have a corded unit in, so you can plug then get the system working.
Then using your software updater update it and the drivers and if you need to get on the logitec website and update the firmware do that to.
The easiest way to do that in most cases, is just to download the firmware, run it as admin, and wait a second litterally while it runs then turn it all off and on it doesn't even come up on the system but yeah.