BuddyPress.org

I would like to increase the avatar/gravatar size to 180px in the member directory page. I use css to change the size to 180px but the images look blurred. I have followed the instruction here https://codex.buddypress.org/themes/guides/customizing-buddypress-avatars/ by adding the following lines to bp-custom.php in the plugin folder but it doesn’t work. The avatar/gravatar still look blurred.

define ( ‘BP_AVATAR_THUMB_WIDTH’, 180 );
define ( ‘BP_AVATAR_THUMB_HEIGHT’, 180 );
define ( ‘BP_AVATAR_FULL_WIDTH’, 180 );
define ( ‘BP_AVATAR_FULL_HEIGHT’, 180 );

What am I missing?