Bug/Issue Side quests breaking in multiplayer.

If one person takes a side quest to kill something, upon trying to do the same the other person will immediately get a "Quest Failed" pop up, and will get it repeatedly as long as he talks with the same NPC that still has "!" over its head. The thing is, when the person that took the quest actually killed the target, the quest still asks to kill that target with the compass pointing into some empty space where the target was killed just a moment ago, making the quest impossible to complete.

From mods I only have Frackin Universe, Frackin Races and Character Extender installed along with 3 minor cosmetic mods (AnTi Hairs, Colorbound and Starface)

FU's author said this should have nothing to do with the mod, so it's probably a vanilla game issue.

Log of the first encounter with the issue: https://pastebin.com/8u41Q6DR
Recreating the issue after restarting the game: https://pastebin.com/PdSfaNa1