It is compatible. It won't show speed unless you have a speed sensor connected to the controller and you set P2 to the correct value. The battery display can get mixed up between 48v and 36v. You have to make it clear what battery you have. If you connect a fully charged 36v one, it can see it as an empty 48v one. You must first connect the battery in an unambiguous state of charge.
On the other hand, it's possible that you've wiped out the display by incorrect connection. If you just push the connectors together without lining up the pins, the wrong pins can still make contact, which can damage the LCD. It'll still have basic display functions.
Any KT LCD will work with any KT controller, but there are sometimes software differences that mean that you don't have access to some parameters or settings.