I had this issue. TLDR I fixed it by going to Services and running the Bluetooth Audio Gateway service. For some reason it wasn't running. I set it to "Automatic" now I can use them as a headset (input and output) on Zoom/skype etc. on W10.
The apps auto-select AG hands-free mode on the headset which is discernably lower audio quality than a wired pair, but for conference calls it works great and the important thing is that the MIC in the headset works in tandem with full stability.
I spent hours and hours researching this on this forum and others - didn't see this simple advice anywhere. Obviously drivers and sound settings are important to have right but the above trick did it for me in the end.
Created this account to share. Hope it helps, couldn't advise beyond this so sorry if it doesn't work for you. I'd start by researching above mentioned service and follow the breadcrumbs.