While the Garmin Connect app is in the foreground (shown on the screen) it works but not when it is in the background.
I got it working by enabling
"Display pop-up windows while running in the background…
With thanks to @lgroth! I have a Pixel XL with settings navigation slightly different:
Settings | Apps & Notifcations | See all xxx apps | Connect | Advanced | Display over other apps | Display over…
Have same problem on s10 plus
While the Garmin Connect app is in the foreground (shown on the screen) it works but not when it is in the background.
I got it working by enabling
"Display pop-up windows while running in the background"
"Display pop-up window".
"Show on lock screen"
These settings are found in the Settings application here
Apps -> Manage apps -> Connect -> Other permissions
My device is a Xiaomi Note 10 Pro running Android 9.
Thank you so much @Igroth! I switched from a J5 to a S10 and it never worked properly on the S10. Now everything is fine!
This works on a Samsung Galaxy 10 running Android 10. Thank you!