Whenever i try to enter ZFW etc., my cursor disappears and the MCDU won't take any input. Clicking any of the buttons below like INIT or C/L Menu resets it until i click the text window again. It happens on any manual number input window on any of the pages like TO PERF as well. This is consistently repeatable with any airport, livery and both the -900 and -1000. The other displays continue to work in the meantime.