Calamity mod bug?

[ᔕﬡᗩᕈᕈᒪᙓ]

This is my second time playing through the Calamity mod and it's incredibly well made compared to many other large mods out there. However, I've seen to run into a glitch involving Supreme Calamitas where even if I'm using some sort of "godmode" to avoid damage, I'll randomly die and get the orange "go to hell" message that is supposed to show when you manage to instantly kill SCal, even if I'm not battling her.

The same thing happened while I was using god mode during her battle, where I would be instantly killed during the bullet hell phase that she starts with and get the same message in chat.

I'm trying to farm for the last few endgame weapons and this is making it extremely difficult because I keep dying for no reason at all. It seems to be happening mostly in the dungeon while I'm trying to farm for phantoplasm. I have the latest update of the Calamity mod as well, if that helps. Any advice or fixes would be appreciated greatly.

Update: it seems that while fighting normal Calamitas, taking any damage from her attacks or contact damage instantly kills me and displays the same message. The only difference between now and before I fought SCal is that I made demonshade armor, but the Calamity wiki doesn't mention this in any capacity anywhere, let alone the demonshade armor page.

Update 2: it seems most hits taken while a boss is alive or an event is active kills me instantly, despite Armageddon not being used by me ever. The profaned guardians spawned during the Providence fight instantly kill me. I seem to also be getting the death message "player's legs appeared where his head should be" which doesn't seem significant other than the fact no other death message shows up when I die. This is getting incredibly frustrating and I for the life of me cannot seem to figure out what's causing this. None of my equipment should be causing this and that's the only thing that's different since it started happening, besides my battle with SCal.