Karoo 3 ends (and saves) ride automatically in (long) standby mode

Two days in a row my Karoo 3 ended (and saved) the ride mid-ride automatically in a longer  standby mode phase while we had a longer break. It saved the ride and I was able to merge the two FIT-files afterwards with a third party app. The first time it happened I thought I accidentally pushed the wrong buttons. But with two times in a row it seems to be a feature or a bug.

My workflow was like this:
- doing a ride with a course running
- pause the ride
- push the standby/display-off-button
- having some coffees (45+ minutes)
- push the standby/display-on-button => running ride was gone (and saved)