You might be thinking of –auto-cleanup but I’m not totally convinced you have excess files when it says you have a missing file. You could try feeding both the missing dblock name and the index file referencing it into the affected command, for example by opening the job’s Commandline. Change the command and put the remote files where the source file list would have been when it was the backup command which is default.
Inventory of files that are going to be corrupted gives an example where a damage forecast is done before intentionally making a missing dblock file then recovering. Your --list-broken-files having no complaint does suggest maybe you have an extra dindex. You could also test moving it elsewhere to see if it helps or hurts.
If you really like, you could make a database bug report, put it somewhere, then link. I can attempt to study.
Your failure, if I follow correctly, was on direct restore, so the following might be relevant to getting your log:
View logs for direct restore from backup files
Whether or not even –log-file-log-level=profiling might help me (there’s SQL but it’s hard to read) isn’t clear.
It would be wonderful if Duplicati someday got better at its repair capabilities, but writing code takes time…