Welcome to forum. Not right place to ask, but I will move it later if needed.
There are several reasons for such a problem.
First of all, if you know which port and baud, you can fix them in the sys file. If you don't know them, look in folder \IGO\save\profiles\01\ there is file system.ini, there Primo record last used port & baud.
Second, there can be some physical problems - Antenna, antenna cable, connector, and unit itself.
And at least, although this version of the Primo works fine on 90% of the devices, it may happen that it does not work well on your HU.
In this case, first try with standard iGO8 (still works excellent on the most of devices), then with Primo first edition (9.2.1), then try with Primo 2.0 KIA edition, and if it does not go well, look for the ESX version. It only has some fundamental changes in the code and has been adapted for some more customized devices.
Yes, all of this will cost you free will and time, but it is for you.

P.S.
In future a little more information is good for solving the problem. That's why I created [Only registered and activated users can see links. ]. Read it
Not everything is necessary for every case, but some items will come to us well and provide guidelines for easier solution.