Fenix 8 43mm trail running GPS measurement is incorrect

I have recently upgraded from a Fenix 6S Solar to a Fenix 8 43mm. Since the first trail run, I noticed that the distance measurement is incorrect - they are measured as longer than they actually are.

Yesterday I had a light mountain-bike ride and today I had a light/medium trail run, on the same routes. Interestingly, the mountain-bike measurement was more accurate than the trail run. For both activities types, I had the 'Satellites' setting to 'Default: Auto select'. I have also used 'All Systems' for a few trail runs, as it reportedly has better accuracy. To no avail - the measurement is incorrect.

A relevant segment is one that I know to be approximately ~2.5 km long:

the mountain-bike measurement

With these measurements, my speed is obviously and incorrectly reported as being way higher than it actually is.

Software version: 13.35, DFU-ebba8d

Any helpful advice is highly appreciated. Thank you, in advance