MRA Navigation Android App no download to SD card

[Achim Haag]

Samsung Xcover 4S Android 11
As my internal flash memory becomes full, I decided to download the offline maps to my SD card.

After selecting "SD-Karte" (SD card) instead of "Gerätespeicher" (internal memory), the Navigation app told me, it has to restart and disappeared (staying active in the background). Afterwards, the setting was still device memory.
Doing the same again but after Navigation app disappeared, I closed the app and started it again - same result.

I found https://forum.myrouteapp.com/topic/4903/problem-updating-offline-maps-on-sd-card , translated the contents and did what I read: cleared "data" and "cache" of the app: same result.

Uninstalled Navigation app, installed it again, registered my account and tried one more time to change the offline download target to SD card, same results.

Is there any setting I missed ?