The 1.15.100.59 beta has made it so that the host's performance is intertwined with the server tick rate. If you give your device an especially taxing load, lets say cranking the render distance to max, you will notice that the server tick rate severely dips in your own world. You will also notice that worse FPS results in the game "slowing down". See the video attached. It is recorded in 30fps and is NOT slowed down. You can notice that my projectiles throw very slowly, there is input lag, my hotbar slots are glitchy, my food doesnt eat, etc etc. My game also looks like its going in slow motion at some points. You can also see in my debug UI that the server time averages between 75-100ms, but the number in infinite worlds can exceed higher values.

https://www.youtube.com/watch?v=k6F-mWeIRrk

I think this issue is caused by the fact that the logic loop (tps) is somehow dependent on the render loop (client fps), and the server is not taking priority. 

I am 99% sure this has to do with the render dragon.