Summoning Modded Bosses in Multiplayer doesn't work

[Plush]

Whenever I try to summon a boss in a modded boss in a multiplayer world, I can hear the boss summoning but the boss doesn't actually spawn. I know it's not from the mods I have, because I got rid of them one by one and the boss summons still didn't work. The modded boss summons work in a single player world, which is why I thin it's because I'm playing in a modded world.
Can anyone please help me? You have no idea how much this'll help

[RMZing]

I'm having a similar issue. Modded bosses are spawning, but the defeat state is bugged. I have Calamity plus a few quality-of-life mods in 1.3. We just defeated Desert Scourge and it's not dropping anything, nor is the game state progressing in our world. A different bug happened with the Eye of Cthulhu where the boss bar remained on the screen and the boss music was still playing above a certain height, even after day broke. Revengeance Mode is not working properly in multiplayer, either.