When I place blocks in Minecraft I tend to get a sudden but short lag spike. It happens every time I place and break a block. I get the fps drop in a specific area on my friend's server. Other players on the server aren't affected by the lag spike. This first started occurring in 1.15.1; I did not notice this in 1.15. In the first picture, my fps is stabilized however when i start placing a few blocks i get enormous lag spikes and start losing fps.
Does this happen in a vanilla server? (You are running craftbukkit)