WP didn’t redirect to canonical category URL

Check error logs – probably PHP sent some content to browser before WordPress tried redirection (and failed because headers was already sent).

Check if you don’t have any ?> on the end of config, theme and plugins files, and ofc check if deactivating plugins and temporary changing theme to one of Twentys help, it could help you target problematic part.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)