There is a long, multi-year thread on the Magnadyne M4 LCD: Magnadyne M4-LCD questions
As I stated in that thread (post #88, I believe) I received and installed three software updates from Magnadyne. It eventually worked okay (still some foibles, but nothing i couldn't work around and live with). I did eventually replace it with a Kenwood and a stand alone Garmin.
Suspect you need the most recent software update from Magnadyne. An SD card. Mine plugged into a dongle out the back of the unit (required removing the unit from the dash), but I understand on more recent models they have moved it to the front of the unit.