Hey, I've just triggered with profiling overlay you see in the top-right of the attached screenshot, and I cannot find how I enabled it. It would be nice to use since I was using my own custom profiler (printing stats) so far but this one has a nice graph and shows clearly when I drop to 30 FPS.

It really is an overlay, not part of the game. As a matter of fact, taking a screen capture with F1 with ignore the overlay!

As a hint, I was reload my game with a script that sends keystrokes Ctrl+R to the PICO-8 window. Maybe I pressed something else, or the keystrokes were not correctly registered at that time, and it triggered another shortcut; which I cannot find at all in the documentation!

Note: this happened in the editor, not the runtime binary version of PICO-8.

Ah, I found it! Ctrl+P
I must have pressed P just when the script sent the Ctrl modifier!