Duplicati Database Recreate running for a week

Does “requesting” mean a restore? If so, you should use this option to test correctly:

no-local-blocks

Duplicati will attempt to use data from source files to minimize the amount of downloaded data. Use this option to skip this optimization and only use remote data.

Don’t restore over a valuable source file of course – use a different folder without any such file already.

In terms of studying the issue, are you comfortable making a copy of your database and looking inside (with guidance), for example with DB Browser for SQLite? If not, linking to a DB bug report might let us (view is not as good, and it’s sanitized for privacy, but it’s one option and there are a few other options).