Watch reboots mid-activity at ca 9km when using GPX navigation

[knurreleif]

Hi everyone,
I’m seeking help with a recurring issue on my Suunto Vertical 2. My watch has been crashing and restarting during long workouts, specifically when I am using GPX routes.

The Issue:
Twice in the last three weeks, the watch has frozen during a walk/run at almost the exact same distance (around the 9km mark).
The UI becomes extremely laggy.
The watch eventually reboots mid-activity.
Once it restarts, the activity is saved and synced to the app, but the recording is interrupted.

Setup Details:
Firmware: Latest official version.
Navigation: GPX route active (I have 11 files preloaded on the watch).
Sensors: Connected to a Polar Verity Sense heart rate strap via Bluetooth.
GPS: Active.
Age of Device: Approximately 7 weeks old.

My Question:
Since this happens at a consistent distance/time, could this be a memory management issue or a conflict with the external sensor? Has anyone else experienced crashes specifically when navigation is active?
Any advice on troubleshooting steps (or if this is a known firmware bug) would be appreciated
Tks.