Loopback error

Hi, I am getting these errors on my site, any ideas how to fix them please? i’m thinking maybe mysql 8.0 is causing one or two of them:

The loopback request to your site failed, this means features relying on them are not currently working as expected.
Error: cURL error 28: Operation timed out after 10000 milliseconds with 0 bytes received (http_request_failed)

And in my Adminer there are loads of “DateTime” & “TimeStamp” errors