I actually read through this section before posting here. I did not think this applies to my situation the way it is worded, as the failed job does not touch the cloned table at all, it only deals with the original table. The creator of the original table might not even know that a clone has occurred, so it is surprising to me that this changes operations on the original table.

I don't fully understand how the shared access mode differs to single-user mode on job-clusters (that aren't actually used by multiple people), but I will enable it for my vacuum job since that seems to help. I do still think the documentation is not perfect in this regard, and the error message mentioning access rights to a completely different table (the clone) is also not helpful.