Hi! There's definitely some kind of conflict with the old drivers, the AC9260 will work just fine with your laptop. Download the drivers again from Intel, then uninstall any kind of WiFi and Bluetooth adapter you see in your device manager (don't forget to tick "Show hidden devices" in Device Manager, you'll find it listed under "View"), reboot and reinstall again.
  I have been having Bluetooth issues after installing an Intel AC9260 into my XPS 13 9350 to replace the Dell DW1820A card, although the WiFi works fine with the latest Intel driver loaded, the Bluetooth fails when you switch it on. You can fix this by running the Repair option on the Intel Wireless Bluetooth software and then happily use Bluetooth, however, when you next shutdown/reboot or restart, Bluetooth will again fail when you switch it on (Windows code 43), pictures attached. Having been through the Intel support suggestions and still have the problem, they have suggested I ask Dell if this card is supported by the Dell XPS 13 9350 as it may not perform properly since the BIOS may not support or be compatible with the adapter. As my warranty is long since expired I am asking you guys out there in the Dell community, the experts, does anyone have an AC9260 installed in an XPS 13 9350 and Bluetooth works without any issues. Any information would be helpful, thanks.   [IMAGE][IMAGE]  
Does an Intel AC 9260 work in a Dell XPS 13 9350 - Bluetooth issues