Mac Monterey "Live Text" Not Working for Imported Screenshots in Photos app

Live Text seems to work in Photos for pictures that I've taken with my iPhone camera. However, I want to use the Live Text on screenshots from meetings. I've imported the screenshot into Photos, with very clear text, but it only wants to treat it as pixels. I can't share the text. Some of it is a bit small, but very clear. On this Mac, I do not have it automatically putting screen shots into photos; I only do that manually for particular screenshots. I'm on an Intel iMac Pro (Intel Macs *do* now support Live Text; early reports that you need an M1 Mac are out of date), with up-to-date Monterey macOS.