Gobthumpers will refuse to spawn a Gum Worm properly sometimes. The worm will make sounds, and the Gobthumper will break, but no Worm will be present unless you go into Spectator and look around for a bit. Judging from some quick testing, it seems to be an incompatibility with another mod? Not sure what could be causing it though. It's not Embeddium's Entity Culling features

I'm experiencing the same issue. Here's my modlist: https://pastebin.com/SwkwsXft