Extreme lag when summer begins/flingo bug?

So I’m playing a solo game as Wormwood and got through autumn, winter and spring with no trouble at all. Everything was running very smoothly. I set down two ice flingos a few days before summer started and they were off so it was fine. But then summer came, and I turned on both flingos which immediately made me start lagging really badly. It’s more of a stutter lag I guess.

I’m not sure if the flingos themselves are bugged because they’re flinging snowballs constantly and just flying off outside of the flingo range and not hitting any objects within it. Even when I turn off the flingos it’s still really bad lag. My WiFi is fine and I’ve experienced summer in Co-op servers (with even more flingos) with no problems... it’s really strange but it makes it unplayable :(

I’m playing with caves disabled and the only mods I’m using are geometric placement, status announcements, and combined status.