Hi all, thanks for the replies. Sorry for the delay in returning here.
So, I’m positive I had tried this before at some point, but clearing the cache seemed to resolve the issue in this case and that seems to have been all it was. But I’m not sure why, because I had tried that on previous attempts. But I had re-created all the settings since then, as I mentioned in my original post.
Anyway, after the backup had been running and failing for quite a while, there were a lot of backups that needed pruned and after letting the prune job run for a looooong time, it didn’t seem to be accomplishing anything. Maybe I just didn’t wait long enough.
But regardless, I wiped my B2 storage one last time, deleted all my configs out of Duplicacy and re-created them, and after that first time failure and clearing the cache, everything has been working for several days now. The backups work as expected, the prune job succeeds, and the check job succeeds.
So anyway, I think I’m all good now. Thanks for the help!