Taking no damage (Calamity+Overhaul, 1.4.3)

I'm well into hardmode on a heavily modded world, and I haven't had any issues with this until the last two days, but very frequently now my character stops taking any damage from enemies whatsoever. If I quit out and re-enter the world, I will take damage, but quite often I will find that I've become invincible again with no clue as to why.

The base of the game is Calamity + Terraria overhaul. Both are on their latest updates (for 1.4.3). I have all the usual QoL mods (magic storage, recipe browser, fargo's mutant mod, etc) and a few other things, such as Decadent Skills. I'm not sure what's causing this to happen, but it's getting on my nerves, cuz I don't want to beat one of the bosses and then realize that I turned invincible halfway through the fight. I thought maybe an accessory was causing it, but even after taking all accessories off my character, still happens.

Any idea what might cause this?
Was this page helpful?