Sorry to hear about your experience. Does it happen with a specific document or all?
Have you tried resetting preferences of the Illustrator? If not, please follow instructions given below and let us know if they help:
Close all Adobe applications.
Go to Location C:\Users\user\AppData\Roaming\Adobe
Rename Adobe Illustrator and Adobe Illustrator 24 Settings folders to Adobe Illustrator.old and Adobe Illustrator 24 Settings.old
Launch Illustrator from the Creative Cloud.
**Please note that resetting preferences will remove all the custom settings and Illustrator will launch with default settings. This way all your old settings will be saved in .old folders and Illustrator will recreate new folders with default settings.