Lag Spikes on empty server

Hello, im looking for someone who have experience with owning servers. My server has 16gb ram and 6 cores and its almost empty, and for some reason from time to time its tps drops to values like 11-13 tps or even lower. All my plugins show barely no use and my only idea is this process but i dont know what is that. I really need help because i cant figure it out

Paper 1.21.3