Page editing in backend redirecting to 404 page not found with url /post.php

Today I migrated a WordPress site from another server to a new server, there is a new domain and new host, so I follow the manual way to upload my site. That was, I downloaded files and upload it on to new fresh host and, database export and import to the new host. After that, I have changed site URL, home page URL in the database, so site looked fine.

But when I try to edit a page, that my back end editing redirects me to 404 page not found. But this issue is only for some old pages while making new page has no issues whatsoever.

After that, I changed all the past domain record matching database records and replace them with the new domain name. Still, I cannot edit my pages.

I tried all the listed ways like .htaccess, permalinks reset, deleting the .htacess and resetting permalinks, but none of that has worked.

Please help me out is very frustrating