Found 1 files that are missing from the remote storage, please run repair #1706 has more comments.
I won’t repeat all the linked forum post, but there are ways there to see if you hit linked issue which looks like error handling during a compact caused Duplicati to roll back its DB transaction, thereby forgetting it deleted some dindex files (delete verifiable through logs and maybe recyle/trash bins).
Forum post reference was to Continually needing repair. I posted clues there, and clues here may be:
(and I’d note that cited missing files were dindex files, which was also the case with my GitHub issue)