I need help (always god mode)

Okay so I’ve recently started a server (1.15) and I’ve been working on it for about 4 days with my brother, we just found out that he is in god mode/won’t take any damage and it won’t let me take him out of it...
I’ve tried /god /ungod /egod and deleting the <username>.yml files and nothing is working. The main plugins I’m using are LuckPerms, WorldGuard, WorldEdit, Factions, MultiVerse...
Any help would be appreciated, thanks.