Garmin’s instructions seem to suggest that devices will need to be factory reset if a power cycle does not work. Reconfiguring a watch from scratch would be inconvenient, so it might be worth waiting to see if Garmin can issue an update that resolves the issue. If you cannot wait too long, you might just have to go through the hassle.

Garmin users from around the world have reported their devices have stopped working or stuck on the startup screen or showing a blue triangle.

Garmin has updated a support page on the blue triangle boot loop issue to provide additional troubleshooting support to affected users.