Here3+ RTK GPS "No GPS Error"

I bought brand new Here3+ RTK GPS and Pixhawk Cube Orange. When I first set up I did what Here3+ manual says, there was a no-fix warning and double blinking yellow led, then I changed the NFT_LED parameter inside the GPS parameters and updated the GPS version and I think after that my GPS is stopped working. The compass is working correctly but there is No GPS. I checked the status of Here3+ and there was no sign of GPS. I reset parameters a lot of times and changed the can port but didn’t work. There is still double-blinking yellow light, but no GPS. I checked the Can ports voltages, and it seems fine.