Unsolvable lags with caves on

[Vihrael]

Hi everyone !

I recently started a new server on my second computer, and experienced hardcore rubber-banding / lags / rollbacks. I'm desperate for a solution after spending hours trying to fix those issues. I did look up on the forums before, but some solutions that worked for other didn't work at all in my case.Turning off the cave completely solve my problem, but loosing 50%+ of the game is a bit sad.

Setup :
-6th Generation I5 CPU 2,7 GHZ
- 12 go RAM
- Geforce 940M
- 512 gig SSD

- Mods on. But turning them off, doesn't change a thing
- Mobile phone as modem. Switching to ethernet on a box doesn't change a thing either.

What I noticed :
- Low latency with the local server (1ms), low latency (<50ms) with external servers  (8.8.8.8), no spikes. So the issues doesn't seems network related
- Long wait chain on the three don't starve processes
- Cpu usage is under 50%, same for gpu / memory / disk usage
- No issues on my first computer (which is way more beefy, but unusable now)
- 55 fps at the beginning, drop to 40 after. Frame-rate extremely choppy
- lags / rollbacks EVERY morning ingame

What I tried :
- playing with the launch argument "-threaded_render" "-tick_rate 60" "-high"
- reinstalling the game
- reinstalling all drivers
- checking Game cache through Steam
- flushing DNS cache
- Changing processes priority
- Admin rights
- A bit of wireshark to look for odd things
- reinstalling libraries used by the game
- Turning on and off lag prediction. It is completely unplayable with lag prediction off. On the worst time I feel that the game update 2 / 3 times per second.

What bugs me the most is that the system resources are unused, and the the game performances are still dropping.

Thx in advance !