I've been desperately trying to get lighting effects to work in PS, as it's needed in my current project. However, no matter what I do, it fails. I just purchased a new 24" M1 iMac w/ 16 GB of memory and a 2 GB hard drive (I couldn't wait to get a 27" M1 - I'll have to trade up next year) and freshly installed PS. Unfortunately, I initially had the same problems with lighting effects that I had on my old iMac - the preview had either all black or all white, with a few horizontal lines where you could just see the background image.
Yes, I did the following: Preferences > Technology Previews > enable "Deactivate Native Canvas" and restarted PS. Now I can see my image and how the lights affect it, BUT, there are no handles or circles defining the lights. So I can't manipulate them. It's useless. This project is on a ticking clock, but I'm fresh out of ideas and I'm just manually adding lighting effects. What a disappointment, particularly with a new iMac. What the heck is up with this?
I finally got it to work, after deactivating native canvas and restarting Photoshop (didn't work); then restarting the computer (didn't work); then reactivating native canvas and deactivating, then restarting Photoshop (didn't work); restarting Photoshop again (finally worked!). Wow ... never have I ever had to jump through so many hoops for a feature to work before. The average user who has this issue will never come up with that combination.
Of course, I have to wonder if I should reactivate native canvas for other features to work. I'm really not sure about what it does. Anyway, I was finally able to use the functionality, along with other features that had worked previously. I'm exhausted.