Frequent Server lag spikes

Hallo Engineers

Since yesterday i have very frequent lag spikes in the dedicated server i host. everything worked fine... there where some minor lag but not to bad. but when a friend connected his ship to a large base the lag started. removing the ship in question doesnt solve it.

First i thought there was a resource loop or something that was frequent but that doesnt seems the problem. The lag spikes are constant every 4 to 10 seconds. the lag spike it self is not even a second but because of the high frequentcy very annoying. The state doesnt really matter. If i walk, fligh or stand still or am in a Cryopod it doesnt really matter. The lag is still there when im outside of the streaming range of all bases and ships in de server.

The servers is a W10 machine with a InterI7 4790 CPU that is during normal server use arround 25% in use (speaded over all 8 cores) 16GB of ram 50% in use. the network is a 1gbps connection. Also the game is installed on a SATA SSD which is 20% in use. Also i have prioriticed the server as high as possible (realtime)

I have tried everything to solve it but im out of ideas. Can someone maybe help me? if you need more information feel free to ask.

Already many thanks