Lunar enemies huge damage boost?

[Marcus BigHouse]

Hi, I'm playing Terraria for some time, and now I'm trying expert mode. I faced the lunar enemies with my beetle armor set and after some tries I finally managed to beat them.. And now I finally beat Moonlord too, and got my first endgame armor set (a vortex set). Now I'm testing it on lunar events again, and the enemies seem to be dealing huge amounts of damage now. I can't even play there for more than a few seconds without dying.
I have 77 DEF, plus endurance potions, and I'm facing the enemies on some platforms full of their specific banners. Even then, I cant stand more than 3 hits before dying even with 600 health.
Sometimes they are dealing more than 300 dmg in a single hit. I went to terraria.wiki.gg to check on the enemies damage there and even on expert mode they cant deal that much damage to a standard naked char. And I'm a well defended char full of banners all around.
I may update a video here as a proof of what I'm saying later, but I would need to edit it and stuff, for now, just believe in me lol.
Anyway, is that a bug or is there something I'm missing here?
Thanks in advance

 

[Dragonlord]

Depending on what you're using and which pillar it is, it could be accidentally you killing yourself, like using projectile weapons at the solar pillar (Selenians reflect projectiles, for instance). Also, keep in mind that banners don't affect projectiles from enemies, which means they primarily are only a damage buff in the Vortex Pillar's case (as that one's spawns are ranged attack based).