Owners of the Swiss tech firm's smart watches have said a strange blue triangle pops up on the device's screen when they go to start an activity that tracks their location, via GPS.

Whereas some people's devices remain stuck on the start-up screen.

Now, Garmin has said in a message on their website that the issue can be resolved if users switch the smart watch off and on.

The message said in full: "We are aware of an issue causing some devices to be stuck on the start-up screen or a blue triangle.

"To resolve this, press and hold the power button until the device turns off, then power it back on, and sync with the Garmin Connect app or Garmin Express.

"If this does not resolve your issue [visit the support section on the website]."