Delays at local and not local servers

So game server seems to have some kind of lag even while playing on local server that is on the same computer.

Things that happen all the time:

- not able to drop items to the ground

- stuck on opening chest animation, sometimes chest opens after 2, 3 seconds, sometimes it just gets stuck

- not able to hit enemies, I hover over lets say spider with weapon in hand and press mouse button to attack, but character moves to the cursor instead of attacking (broken hitboxes in windowed mode?)

- kiting is impossible, i press f or mouse button to attack enemy once and insdead of one swing my char does 2 or even 3 swings (caused by lag? but there should be no lags on local server?)

Need some help with those, playing on steam windows version in windowed mode.