In 60fps carts, using "." to advance a frame will skip a frame and advance 2 frames instead.

n=0

function _update60()
 n+=1
end

function _draw()
 cls()
 ?n,30,0
end

To reproduce, run the code above, press ESC, and advance with ".".

If you instead put "n+=1" in the _DRAW() function though, it will not skip, essentially behaving like a 60fps cart running at 30fps:

n=0
m=0

function _update60()
 n+=1
end

function _draw()
 m+=1
 cls()
 ?"update: "..n.."\ndraw: "..m,30,0
end

I wonder if the time the cart is stopped is being included in the frame/draw time, causing the wrapper code to skip a draw to try to catch up.

this bug is still a thing in 0.2.4, I also made a demonstration gif