Could not save database on chromebook/gdrive

I installed KeepassDX and keep a shared kdbx file on GDrive (to share the crypt between phone and chromebook). With the database closed on the phone and opened on the chromebook, I cannot make changes.
Every change results in "could not save database".
KeePassDX version: 2.9.2 (from the playstore)
ChromeOS: Version 88.0.4324.22 (Official Build) beta (64-bit)

Start by reproducing the save failure with KeePassDX 2.9.2 on ChromeOS 88 using a shared kdbx file stored on Google Drive, while the database is closed on the phone. Done means changes can be saved successfully in this setup, or the limitation and supported workflow are documented.

Written by the indexing model from the issue text.