I have a Wordpress site recently migrated from a shared hosting in SG to a managed VPS in USA.
After the migration, everything works fine site-wise.
Except for 404 not found pages that I encounter everytime I click certain on certain "save settings" link from the dashboard.
Whether it is "save settings" for plugins, or Wordpress basic features, some of them always redirect me to 404 not found. But some others are always working just fine.
I need someone to help me fix this problem
mod_security has been whitelisted by the VPS thus doesn't seem to be the culprit.
.htaccess is also fine.
tried replacing the wordpress wp-admin with fresh downloaded files also doesn't work.
I have 7 years of experience in WordPress development. I have past experience with this kind of issues. I can fix this in less than 10 minutes. Ready to start right away.