You can use the following code snippet to increase image dimension.

function wbcom_custom_cover_image_sizes( $settings = array() ) {
$settings['width'] = 1920; // Your desired width
$settings['height'] = 1080; // Your desired height

return $settings;
}
add_filter( 'bp_before_xprofile_cover_image_settings_parse_args',…[Read more]