Premiere Pro Danger stripes after render

[Piecloud]

So I've just finished edirting a rough cut, exported it out and quit premiere. Once I saw I needed to make a change and opened the project file again, I saw that half of my timeline is covered in danger stripes. 

No files were moved, all the media is on a built-in hard drive, absolutely no changes were made. I did not update Premiere or even put my PC to sleep in between. 

Revealing in project and replacing with clip from bin method doesn't help, I am getting all the wrong i/o points and everything goes out of sync. Relinking doesn't help, in fact I can't even properly unlink the files - they stay covered in stripes. 

Very frustrated, over 6hrs worth of work is trashes because of this. What is wrong with my premiere? 

Running on Windows 10, Premiere Pro 2022.2.0 (Build 128).

[Piecloud]

Here is a snapshot of the timeline where I synced the three cameras of one interview. It's all three files, but only the first half of the clips is in danger stripes and those bits are also now showing the "beginning of clip corners" on each bit that I cut. But it's all one file. I don't get it. 

[Ann Bens]

FAQ: What do I do when I see diagonal lines on clips

[Piecloud]

Thank you Ann, but as I indicated in my post, I have already tried the methods descrideb in this article.