Hi there. This sounds EXACTLY the same as my issue. After contacting Garmin, I was sent the following, which I followed exactly and it has fixed the issue. I hope it helps:
Firstly, I would advise to make…
Just a few days ago i had the same thing happen. Edge 520 worked fine one day, next day the bluetooth just wouldnt connect.
The 520 shows the phone as paired, but disconnected.
i have done a reset on the…
Thanks friend, worked for me with a Moto G 5G Plus and Edge 520.
Had the same issue pairing Edge 520 to my new Galaxy S20 FE. Tried several times with no success until I uninstalled the Garmin Connect app on my phone and reinstalled it, then click the 3 lines in the left upper corner, scroll down to Garmin Devices and click the bottom blue button Add Device and follow prompts. Do not click OK on your Garmin when it shows you PIN until the phone is paired. Good luck!
I used samsung smartswitch and the Garmin app moved to the new phone. I thing the problem is the Garmin can only connect to one phone. So firstly I had to go into my new phone (S21) and unpair the Garmin (which smartswitch bought across). then on the Garmin I removed the old phone (S7). Then on the Garmin under Bluetooth I got Menu > Settings > Phone > Pair Smartphone.Dont forget to accept all of the permissions. Now the Garmin and new phone are paired.