1.15 is broken.

My game is at a constant 60 FPS even though I have put the limit on Unlimited.
Still, the game sometimes performs as if it was 20 FPS, even though it says it is 60.
My computer had well over 200 FPS on 1.14.4, and it still does when I revert to that version of the game.

There is also an issue with Signs in 1.15.
There are hollow commas between every letter on signs. You can see through the sign in these hollow commas.

When interacting with certain things, such as Chests, my character moves his hand twice instead of the usual one time. This is also a 1.15 bug that I do not have when playing 1.14.4.