Language settings constantly reset

I use OSMC for some years now, and just recently I did a clean install with the latest stable build on a rpi2. I use national language settings (German in my case). I still face the problem that language settings are lost and need to be repeatedly set after each reboot.
Can this be solved? Am I missing a setting option?

Did you update to the latest version after the reinstall? Which version is shown? Because you might be impacted by this issue

Alternatively it might be an issue with your SD Card being read only. Are other changes (e.g. skin) permanent across a reboot?

Yes. I regularly update and have the latest build. I never had sad face though. Changing language works until reboot. All other settings remain as I did them, and I do some. Just the regional settings are affected.

Enable debug logging and provide logs after the language is reset either via MyOSMC or grab-logs -A