Time Machine file hierarchy being added to - folders have been added

some 2 weeks ago I got my computer back from Apple service in which they had to wipe it. I restored the time machine backup with no issues and have been using it since – waiting to make sure all is running smooth before doing another back up. I did the back up today and when I took a peak at my external backup directory I noticed folders in the back up directory which have been named w/ appended names and which I do not have on my original file structure or that show mounted in disk utility. When I called apple and showed them and asked, what were they, the advisor said, "Great question – Shouldn’t be doing that. Ive never seen that and don’t have a precedent for that." They had me run First Aid on my external drive. Ran with no errors reported.

Question: Why were the folders added/renamed with the 1 and 1 1 suffixes? Is this normal behavior and what does it mean?

Current disk structure from disk utility

Folders from Time Machine backup

here is the back up progression and then the latest back up before this service a few weeks ago. there was. no change in directory structure from no. 3 backup and last b4 service so I skipped all those.