There are two scenarios where users are affected here.

My screen is unresponsive from the second I turn the printer on:

Did you just do a Firmware update? Try re-installing the firmware. It's possible that it was just a partial update.

My screen becomes slow or slightly unresponsive after 24-48 hours:

This is a known bug in the latest firmware and is being addressed. It is solved by rebooting the printer.