Unable to edit a raw file and can't duplicate layers - help! [Unable to edit in Photoshop CC 2019 after sending from Lightroom]

I normally edit my raw images in Lightroom CC Classic and once most changes have been made, right click on the image and "Edit in -> Edit in Adobe Photoshop CC 2019". Last week, after one of the recent updates, I can no longer edit my images in Photoshop. I can send the image there from Lightroom, I can see the image in Photoshop - but I simply can't edit in there. All of the menus are greyed out - so for example, I can't duplicate layers etc! Any help would be warmly received. Photoshop is version 20.0.1.