Please help! I can't find the button to share my screen during Zoom meetings!

I had no trouble doing this in the last two weeks, although I don’t recall the exact date when I last shared my screen.

I'm running the latest zoom under Windows 10 with NVDA. I have a Pro account, and I am the host of the meeting.

Before, I would simply press ALT+S and then specify what I wanted to share. But pressing ALT+S seems to do nothing now, and tabbing through the meeting controls does not take me to a Share Screen button.

I can't seem to find anything in my local settings or the meeting scheduling options that would affect screen sharing either.

I'm stumped, and I am giving an important presentation in two days time to sighted people, demonstrating how I navigate a Website using a screenreader.

Any help gratefully received.

Chris

P.S. I’ve also checked in Settings in both the Hotkeys and Accessibility categories, and nothing seems amiss there either.