MacOS – Don’t see “Bluetooth Radios” and bluetooth not working on Bootcamp Windows 7

The frequency of 2.4 GHz Wi-Fi overlaps and can interfere with the Bluetooth frequency that is going to the keyboard to the Mac.

Some PC have better response with this fix:

You just need to go into your Wi-Fi settings by going into the browser and entering the router's IP address (usually "192.168.1.1"). Enter the username and password when prompted. There should be a wireless setting for your wireless frequency, called 'channels' and normally is put the 'automatic' you just have to change that from 'automatic' to 'channel 1' this should out your router to the lowest frequency. After saving the settings just to be sure turn off the router for 30 seconds and check your keyboard if it is working (may need a restart of the iMac and the keyboard). This should resolve the problem.

Your bluetooth controller is probably kaput. If your MBP is under AppleCare (hopefully still since it's a 2014), this should be covered under warranty. I would take to the local Apple Store for service

If not, go to your local electronics retailer (Walmart will work here), get a usb bluetooth dongle, install and see if devices can connect.

If they can, then you have narrowed down your problem to the internal bluetooth. You may be able to find a BT module on eBay for a nominal price. They are fairly easy to replace. But if you aren't handy with a screwdriver, a local "Geek" could handle this task.