[2.0.20] Demolishers UPS drop (Solved)

[doomguy4]

I started experiencing extreme lag 2 days ago on a server me and my family setup. The lag started when my cousin started exploring more of Volcanus.
I downloaded the map and tried playing it locally and I get UPS of 45-50.
It was only the 2 of us online when this started happening and we where not working on any major changes to the factory.

I did notice something that looked a bit odd to me, the update is taking 20ms average, but adding up all of the children of the update only counts for 9.4ms of that time.

Also when he killed 50+ demolishers the "catching up" dialog after connecting to the server stopped going backwards and instead just floated between 40%-60% for 5 minutes.

Edit:
~150 demolishers killed and UPS is now back to 60 and update time is averaging 10ms