I have this issue on my head unit AHV-Z9250BT.
Does anyone try this seller on ebay?
AVH2AVIC - Pioneer AVH-Z9200DAB AVH-Z9200BT AVH-Z9250BT update to AVIC - SD card | eBay
They claim to upgrade the software for AVH-Z9250BT to AVIC model which has build-in NAV as well.
Or if you can share the firmware for AVH-Z9250BT will be appreciated
Thanks,
Ron