wp-login.php not working goes back to home page

If i enter mydomain/wp-login.php it does not open the sign in page but goes back to the home page. However, if i enter mydomain/wp-admin its working it opens the sign in page and it shows the url https://mydomain/wp-login.php?redirect_to=https%3A%2F%2Fmydomain%2Fwp-admin%2F&reauth=1

I use buddyboss theme and the header in the front end "sign in" links to wp-login.php and since its going back to the homepage we cannot sign in. How to change the link to wp-admin or fix my wp-login.php

I disabled all plugins but its the same problem.