BuddyPress.org

I think you can’t show the correct number, because you do the test about role of bbp_blocked in the loop, so the number of members is uknow before the loop, buddypress save the number of members before the loop in variable $total_member_count

check bp_core_get_total_member_count() function.

I think if you check how buddypress profil search work, you will find a solution for your problem.
https://wordpress.org/plugins/bp-profile-search/

Regards,