Hello,
I have the same error which drives me crazy !
I made several test and it seems this cames from WordPress 6.4
I made all my test on a fresh installed WordPress 6.4 with no plugins and this error appears in the tools/site health.
Very annoying issue because on the production website it blocks all the updates and the website is very slow.
When I downgrade everything returns to normal.
Hope there will be a fix soon.
John