Today the watch totaly crashed by starting a run.
Hard reset does not work, i see only the triangel.
was updates.
All,
We are aware of the disruption of devices displaying a blue triangle when starting a GPS activity. Holding the power button until the unit powers off may or may not restore functionality temporarily…
All,
Thank you very much for your patience as we worked on this issue. Please see the steps from My Garmin Device Will Not Boot Past the Start Up Screen for a resolution. If you already performed the steps…
Although appreciated, it's completely absurd the only guidance we have are some other users suggesting button combinations to get these devices to power back on but not resolve this issue. Where is…

Yep, bricked Forerunner 255. I started a walk and flashing triangle. A soft reset does nothing.
I'm not using beta firmware; had an update about a week ago.
Additionally the Connect app on my phone…
Just got similar problem when my Forerunner 255 suddenly starten to have a blue triangle blinkning. It happened eventhough no activity had been starten. The only thing wirking is to closing down the watch by pressning Light Button for 15s. Starting it up again only results in the blinkning blue triangle.
I encountered the same problem. The first activity in the morning went without problems, after the second I got an endless reboot loop. A reset with three buttons helped me. But I noticed that in the "bicycle" activity I can't change the background color to black, neither through the watch nor through the app. I hope for an update to fix the problem soon.