Garmin Fenix 8 users flag important issue with dive watch 

Users of the recently launched Fenix 8 AMOLED smartwatches have reported problems with the smartwatches linked to cold water. On the Garmin Forum and Reddit, customers have flagged that the wearable shuts down or restarts in situations with cold water, such as an ice bath or swimming.

This problem only appears to affect customers with the Fenix 8 AMOLED 47mm and 51mm models; the MIP Solar smartwatches seem to be working as expected. Wearable users reported experiencing the issue in water temperatures between 6° and 13°C (43° and 55°F). In the user manual, Garmin states that the smartwatch can operate underwater in temperatures ranging from 0° to 40°C ( 32° to 104°F), so these customers should not have experienced this problem. Plus, the Fenix 8 is advertised as dive-certified up to a depth of 40 m (~131 ft), where temperatures are likely to be cold.

According to some users who have contacted the company, Garmin says that this is a software issue, while other sources say this is a confirmed hardware issue. Garmin has yet to officially acknowledge this issue, so unfortunately, there is no explanation or resolution at the time of writing. If you own a Fenix 8 smartwatch and are experiencing this issue, you should contact Garmin Support.