Yesterday my Pixel 4 phone received the December update for Android 10, and I noticed that one of the fixes mentioned in the release notes was "Fix for pairing issues with Garmin devices". Sure enough, when I powered up my 1030 for a ride this morning, it immediately connected to the phone. Previously, to get a connection I would need to wait until the 1030 had finished booting up and then restart the phone, after which it would connect automatically. See https://support.google.com/pixelphone/thread/21769134?hl=en.