Cannot write to WebDAV mounts with Keepass

I have set up my Murena Cloud in the Account Manager under “WebDAV mounts” to access my kdbx database with Keepass2Android or with KeePassDX.

Opening and reading works, but saving (writing) does not work, neither with Keepass2Android nor with KeePassDX.

Does anyone have any idea what the problem is?

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

I have now found out for myself why this does not work:

Also, not all apps support content from remote files (SAF). If you can’t open a WebDAV file with a specific app, chances are high that
the app doesn’t support remote files at all,
or the app opens the file in read/write mode (which is currently not supported by WebDAV/DAVx⁵).