Noticed i was not getting notifications on watch for a while now. Largely ignored it thinking i probably didn't have watch linked with phone. Finally discovered i actually can't pair it at all.
After more digging realised the mac address of the Garmin instinct 2x Bluetooth is showing as 00:00:00:00:00:00.
Tried a watch reset, that did nothing. Spoke to garmin support who said to try Garmin Express and interestingly it did seem to add a Bluetooth software update to the watch even tho i was already running latest 16.11. But unfortunately the update installs and restarts the watch, but the issue remains. The update is still available to install and i can try again and again but no luck.
Noticed other Garmin watches have had this issue going back many years. So, it's probably safe to assume the Bluetooth is dead and I'm out of warranty. Can't say I'm too impressed it's still a very new model watch and should not suffer this sort of failure so early on.