Illustrator did not save to cloud for a whole day!

Online data storage, aka "the cloud," can be very convenient. But I only use it as a repository for commonly used art elements and document templates. I don't trust the cloud for saving design projects while I'm actively working on them. I very much prefer saving to a local hard disc. It's a lot faster and more reliable. Then, if I want to do so, I can copy the file into a cloud-based folder.

I agree with Mike Gondek's suggestion of periodically saving files manually. I'll click Ctrl+S on my keyboard from time to time while working in Illustrator. I do that when I finish a significant portion of a project or if I'm about to do something that I know is going to strain the computer system.

Astute Graphics has a pretty neat plugin called Autosavior. The plugin can auto-save files on a user-defined timed basis and can create multiple back-ups in multiple locations. The plugin can be had for free. All it takes is starting a trial of Astute Graphics' plugins. The plugin can be kept for free if the trial is cancelled.

https://astutegraphics.com/plugins/autosaviour

Did you do any manual saves? Auto save & cloud are nice features, but for reasons like this I like the old school manual save to drive where I see the file. I have never lost a file in over 35 years of using Illustrator daily.

Do you have more than one account. I have my work and personal license, if which can easily get confused. Also check if you have more than one filename, you may be laoking at the old filename.

It is always best to save locally as well as on the cloud. Adobe can't be responsible for internet connections and that is really what it comes down to. If you are not connected, Adobe is not going to know. Sorry for the loss of your work.