can't edit site url wordpress

I’ve changed domain and can’t edit URL from homepage.com to homepage.com/
with / on the end. I try to change in Admin and its not working. in Phpmyadmin I have with “/”. I’ve tried on wp-config define both the “WP_SITEURL” and the “WP_HOME” values. And Still I have domain in format: homepage.com without / on the end.