So, I have an Arduino Mega/RAMPS 1.4, with a 20x4 LCD panel and a rotary encoder. I am using Marlin for the code.
Everything is hooked up, code modified and compiled without any errors.

When I first start the rig, the encoder will control the flow rate. I turn it clockwise, the flow rate drops. I turn it counter-clockwise, the flow rate increases. If I click, the screen switches to the menu. All of this tells me that the electronics and wiring are solid.

Now for the problem.
Once I click into the menu, the rotary stops working. I can click back to the monitor, but the rotary no longer works there either.

I'm thinking that when the screen is changed, the focus for the encoder is not being set. However, I am having trouble finding where the code calls the encoder controls and what happens when screens change.

Any assistance that might point me in the right direction would be appreciated.