Find command lists all files in backup instead of specified file is the prior report, but lacks explanation. Experimentally for me, the --exclude that I added is behaving like an --include (which works like itself).
The FIND command says what should be happening. Feel free to file an Issue for a developer to look:
--include=<string>
Reduces the list of files in a backup to those that match the provided string. This is applied before the search is executed.
--exclude=<string>
Removes matching files from the list of files in a backup. This is applied before the search is executed.