This issue was solved with a newly bought SD Card of the same type (also SAMSUNG 64 GB) which was formatted as internal storage without problems. The old card mysteriously works fine in a different device where it was formatted as internal storage without problems.
Hi. I’m wondering, is it possible this way that apps with large storage requirements will end up on the sd-card (e.g. navigation with offline maps, etc.), even if they wouldn’t support sd-storage out of the box?