I'm sorry I've been slow at responding. I get migraines pretty often but this past weekend/week they've been brutal (partly because I'm sick).
I talked to . For some reason the Slytherin house group ping was restricted so only admins could ping the group. I'm not sure why or when the restriction was placed. I could have sworn non-admin users have ping the group before. Anyways, I fixed it so now anyone should be able to ping the group. c: