Hi there, we tried both on the same lan network and happened both times. Lan doesn't seem like actual lan, I feel like it goes out to the internet first and then back in. We don't have the greatest internet so this might have an effect on it. It would be nice if lan was lan where only people on the network can see our games. 

Oh the map was called Wetwork. Creatures running into walls like they're not there (multiplayer). Trying to run over the arena with no avail.

Enemy creatures being 'picked up' by npc players leaving behind a bunch of above head level icons all over.

Creatures stop functioning: all my cultists just stood still indefinitely for example.

My specs

Windows 7

24GB RAM

Core i5

GTX 1060

This is also happening for my partner who was one of the other players. Other 2 players were computer.

His specs

Windows 7

16GB RAM

Core i5

GTX 960

I am not sure how to make a video of it yet, looking into that.

Ah sry I didn't realise I had a reply yet. I have actually not had a problem with it recently. I was on multiplayer over lan, on the 4 player map called Flower. I am going to play that map again to try and see if it was just a connection issue on that particular day or if its the map.