Dexcom user here, but I believe the technology is very similar?
Does the libre make your phone sound an alarm if it goes out of range for too long? My dexcom does, which means I'd be alarmed if it lost connection at night. But usually mine just loses connection when I'm too far away. My fitbit watch however (bought so that I don't have to fish my phone out every time I want to see my bg) loses signal a lot. But this doesn't matter because my phone alarm will wake me if I go low overnight.
Maybe there is a setting which allows you to get your phone to alarm if it loses signal? Otherwise, you could try phoning the abbott helpline for suggestions, as if they don't know there is an issue they can't fix it.
Good luck.