The rumors (I haven't experienced yet, but I am no hardcore Primo user :girl_flag_of_truce:) are well known: entering a tunnel and having a route set , Primo crashes and GPS device restarts. First one who mentioned it to me was Xtyler92, I believe.
When I remember correctly, he said this happens without exception on several (Chinese) WinCE 5.0 and 6.0 devices, with the original ...