Video thumbnails and video timeline not showing video in iMovie. Worked fine yesterday.

I am new to iMovie. But I like all Apple products so they seem the best logical fit. All my software and hardware is completely up-to-date or brand new. Top-of-the-line MacBook Pro from a year ago… And mac studio purchased eight months ago. Started working with iMovie. Imported clips. Started editing. Made a ridiculous dumb video in the timeline with the edited clips. Everything worked great. Even imported music as well. Quit iMovie and launched it in the morning. Everything fine. Tonight, I re-launched it and while my other libraries have all of the imported clips from a couple of other projects, the one that I was working on last night, just shows the clips within the import section and it also shows the clips still in the timeline. The only problem is they're all blacked out instead of showing a thumbnail. And while the playhead moves perfectly and the audio track beneath it plays the music, no video can be seen. This is driving me crazy. Should I go with something else?

It's weird as I made a thumbnail of the photo below more photos started showing up hours later. This is ridiculous. Can anybody explain this? If you look at the timeline, there are no thumbnails at all. Nothing plays. I don't know why my Internet connection would make a difference as this is all in my local hard drive obviously… But the Internet connection is at 1:20. So fast as you know what. Don't know what else it could be. Any help would be greatly appreciated.

I know this community system moves slow because you have to wait for responses and then you respond and then wait for responses, so I figured I'd give as much information as possible. As I stated before iMovie is up-to-date, operating system, completely up-to-date and I've started and restarted several times already. So all the basics I believe have been covered. Thank you.