I experienced the 24H2 'upgrade' crashing my OS due to incompatiblilties with my nVidia 3070 TI card and the associated drivers.
After several attempts, to both get through the upgrade and numerous failed attempts to engage Microsoft or nVidia on the topic I simply rolled back and waiting.
Eventually, after monitoring nVidia driver updates, I attempted again and then the upgrade completed successfully. I paused updates for about a month in that time which I was very uncomfortable about.
No idea why the problem happened and neither MS nor NVidia acknowledged the problem or announced they had fixed something but... someone clearly did as it has been fine for several weeks now.
Sorry I can't be of further help/advice.