You need to set Headset BHS as default device instead of Headphones BHS, and same for input, and also for Loconius, actually its stereo also with Windows when set to headset just lower bitrate than android and IOS, that is a decision that was made by the Bluetooth stack developers on Windows, they can choose to stream at a higher bitrate but you will lose range, bluetooth range depends on bitrate, for phones it was assumed you are always in max 5-10m range, I can get with my headset on Windows 10 with stereo sound (high bitrate) tru' 3 concrete walls and about 20-25m and I can still get perfect sound, something my phone will not do even when just playing music, in a call its even worse cause Android and iOS also switch profiles from A2DP to handsfree different bitrates but still worse than pure A2DP
EDIT: A Clear paired devices on the headset/headphones is recommended and also you should remove the devices from paired devices in Windows, then pair again, and without any apps opened that use the mic, set for both recording and playback the "Headset" device
This should work on Windows 8.1 and up, I have tested this with bluetooth 2.0 (or2.1) from a Lenovo T61 from 2007 and it works perfectly on 8.1 and latest version of windows 10 with my headphones (Sennheiser HD.4.40)
Feel free to write me for any more help :)