Issues with video and cell phones

I have been using Doxy.me successfully on a Windows 10 desktop computer with a Chrome browser and a USB webcam. Yesterday I started to have a problem: my client could not see me and my shared screen, or hear me on her smartphone. We were able to text each other through Doxy.me, though.

I’ve done some testing. The problem also occurs in the Edge browser on my desktop computer. It does not occur if somebody links to my desktop computer from a Windows 10 laptop. It does not occur if somebody calls from an iPhone to my laptop.

So, the problem may not be with Doxy itself but with my desktop computer. However, it used to work on my desktop computer and I am not aware of any hardware, software, or settings changes to that environment. Has anybody had this experience and was able to fix it?