I have only had the VivoActive about 4 days (I got it on Monday about 6 p.m.). Within those 4 days, my HTC One M8 phone was upgraded to Lollipop 5.0.1 and began pairing intermittently. I was trying to figure out what was causing this. It seemed that I had to keep the Garmin Connect Mobile app open on my phone all the time and that if I got more than 30 feet away from my phone, it disconnected. I was questioning the usefulness of the watch if I had to keep my phone right by me all the time although I do take it with me everywhere (but not when working in the garden or walking around my house).
Eventually, I read somewhere to reinstall Garmin Connect Mobile and to turn the phone off and on again. Reinstalling Garmin Connect Mobile only made it impossible to reconnect the watch to the phone, when before the connection was intermittent. Now the Garmin Connect Mobile app icon does not show on my phone, but if I go to the Play Store, I can open the app from there. I also noticed that on the watch's system menu, there was an item called BlueTooth and a couple of swipes later, one called something about pairing. When I tried that item, the app went into black space. I had to uninstall it and install it again to get it running again. At some point, that pairing menu disappeared so that now there is only the menu called BlueTooth.
So I think the problem has to do with Lollipop being installed on my phone. The M8 phone is not on the tested and approved by Garman list, although the M7 phone is. Since the upgrade to 5.0.1 is so recent, my assumption is that Android version 4.306 that I had before may not have been tested and approved, but it was working fine before the upgrade. The specs on the M8 say that it has Bluetooth 4.0 Smart Ready.
Is this something that can be fixed at your end? I can probably use my iPad mini to pair the watch, but then do I have to have it within 30 feet all the time for the watch to work?
Given my limited experience with the watch, I am not sure what to expect or what to try next. Any suggestions? I will speak with HTC tomorrow, but maybe I should be speaking to Google. Maybe Garmin should speak with Google since the watch paired before and was working fine. Maybe your speaking with Google would lead to your knowing how to fix the problem or your having Google fix the problem. I really don't want to have to return the watch. Is anyone else experiencing these problems after an upgrade to Lollypop?