I too am having problems with the Libre2, I had used the original Libre for a long time without a problem, but changed to the Libre2 in August last year since then it's been a nightmare. The sensors stick fine but after 6 days the reader and app on my 'phone just says no active sensor...
I'm a type 1 diabetic and I also get disturbed vision, auras etc, I find I get them more often when my blood sugar's are low, that seems to be the trigger for me. Hope this can help