Reboot during activity with loss of training status data

Hi all,

In the last two weeks, my Garmin Edge 830 did a reboot during my activity.

My biggest frustration with this issue, is that my training status not correct due to the reboot. In an activity of 150km and 126km, my device did a reboot, and based on the training & nutrician data, the device forgot all data from pre-reboot and only registered the data after the reboot. Any other data like heart rate, cadance, power, ... is not affacted. However what I could notice is that my altitude took a big upstep actually, and I was not climbing at all. See the picture below.

My device is according to Garmin Express on the latest FW (9.40) and I'm on European maps.

Anyone faces the same issue and has a fix for this?