IOS12 to Win10 bluetooth connection problems.

apologies - newbie to iPhone. Issue: bluetooth. XR's (2) and iPad Pro running IOS12.1.2 will not connect to Win10. Other devices (e.g., android phone, headset(4)) connect and communicate fine. I updated the bluetooth drivers, then tried again. All other (non-apple) devices still connect just fine, XR*2 and iPad Pro will not. Bluetooth has worked great to transfer media to/from devices, trying to figure out why XR/iPad won't allow it either way. Especially do not understand why connection is 'not supported.'