I just got off the phone with Garmin customer support. I'm having a problem connecting my 520 with a Moto X Pure running Android 5.1.1. I'm using the latest Garmin Connect app v3 but this also occurred with the previous version. The 520 also has the latest FW version. Going through the app I'm able to pair the 520 and the phone together. I get the same pairing code on both. But immediately after the 520 and phone disconnects. I have a Garmin 920xt with connects and I have no problems syncing between the two. I also have a couple of headphones and my car audio system connects and a Basis Peak fitness watch that connects. I'm just having the problem with the 520. I'm currently syncing by using a usb cable to my PC. Garmin Support and I went to through several things, removing all the existing connections and repair but the same thing happens. I earlier had hardware reset the 520 and that didn't work. Garmin Support finally said that they don't know what the problem is and that my phone is so new that it isn't on their approved phone list.
Has anyone else had this problem with a Moto X Pure or any other phone? Any recommendations or thoughts? There should be an Android 6 update coming for the phone at the end of the month or early next month. I hope that fixes the problem.