I am playing with a friend on his game. And when I wanted to change the maximum input or output charge for a Mk2 factory building, nothing happens.
I have checked the keybinds and they are set to Control+R for Decrease, Shift+R for Increase and R for Direction.
But when I try to use the keybinds nothing happens.

Just to check, you are hovering your cursor over the yellow arrow near the exit, right? Or are you talking about a chest or fluid connection?

Im currently thinking about the electrical connection