@android I used
adb logcat
and pinned it down to the error message
bta_gattc_mark_bg_conn unable to find the bg connection mask for: […]
It matches well to this espressif issue: https://github.com/espressif/esp-idf/issues/5395
However, I don’t know whether #espressif is involved in #suunto at all…
@normalexit out of curiosity: Why not a plain debian? What are the benefits of Ubuntu server?