I had this happen ,I replaced the MicroSD card,reloaded the database and its been fine ever since!
The Micro SD that comes with this is a Piece of Crap! The radio is great! Dont get me wrong,I am using a 16GB.
A quick fix is take the batteries out and try again but something is corrupt,and thats whats causing it to lockup!
It cant properly load the database ,so it gets "stuck".When you reload the database use an SD card reader ,thats the best way.