Can’t access website as admin, only as editor or less roles

The wp-login.php URL you are taken to often has additional parameters added to the URL. This can cause a login loop. Try manually typing in the login URL only and going to it to ensure no added parameters are in place. Log in again. If you still get taken back to the login screen, try manually typing in the /wp-admin/ URL and going to it. You may already be logged in even though you keep getting redirected to the login screen. Manual entry should break the login loop.

It’d be a good idea to first try this with no plugins and a default twenty* theme active to ensure there is no other influence on the process. If you can login, restore your plugins and theme and try again. If you then have trouble, one of those modules is the cause. Selectively deactivate to determine the source.