Just come across this after posting my own thread. I’m having issues getting my phone to scan my sensors to get them started. Just this evening I attached a new one, no matter what, it wouldn’t scan. So peeled it off and tried another one. Same problem. Searched the internet and come across a few references to the latest apple iOS update not being compatible with the Libre app and sensors. I looked out my own old iPhone which doesn’t have the latest update so downloaded the app and hey presto, it scanned the sensor straight away!
Really not ideal as I prefer to just use my new phone. Personally feel this needs well highlighted as system is defunct. Going to see if I can get a reader as a back up