Controlling a servo motor with two arduinos?
You can't just connect random pins together like that. Connecting two output pins together is a recipe for disaster. Best case scenario: nothing works. Worst case scenario: you break one or both Arduinos.

Only one Arduino can control a servo. If you want a second Arduino to make something happen to the servo you have to make it tell the Arduino that is controlling the servo that something should happen.

That could be a simple output of the second Arduino connected to an input of the first Arduino, in which case it kind of acts like a button. Or you could create some kind of communication channel between them - maybe using a Serial connection, or a Wire (I2C) connection. There's many ways, and which is best depends on how much control one Arduino needs to exert over the other.