Don't know if it's a bug or feature. I've got the cyber boars event in the endless gamemode, but this seem to be in cycle. They keep respawning for 2 ingame weeks already and im just fucking tired of them.
Maybe this will clarify, I've got lucky some days after boar invasion and got bad sun event and after that the red sky event. Don't know if it's connected tho
Edit: I've killed like 12+ of them and im on the day 56