I threw together some code to visualize the hiccups; they are within the first 15 seconds (repeatable) and after that it is a rock solid 59 to 60 fps (green).
The bottom row is first 15 seconds (up to vertical line) and then it keeps plotting framerate and moves up a row at a time:
The glitch on top row is when I used “Snipping Tool”.
I went through many of my apps to see what cause hiccups (frame rate drops) and was very surprised! Some had no impact and others significant.
I’ll clean up code and post later.
glv