Strange maximum history limit behavior

CopyQ 9.1.0, Windows 10

CopyQ stop saving items in history for a few days now. I did a quick investigation and figured out something odd.

So what I expected - I have history limit 1000 in setting and I thought that after reaching this limit new items will override old ones.
I deleted three items from history manually, next three new items were saved as expected, then saving was stopped again.
Then I increased history limit to 2000 items and new items began to save again.
BUT it showed me 2000 items in history tab immediately. I looked in the folder where they were stored and there was ~6300 files there. Last file was named copyq_0004.html and dated 02.11.2021! Obviously not every item was saved from 2021 only some of them.
AND every item that I copied while CopyQ wasn't saving them in history tab was presented in folder.

After i deleted most of the history from folder new items began to save as expected. BUT(again) most of items are shuffled in history tab now.
I even do not have guess what the main bug is or how to reproduce it from scratch. Nothing strange in logs.