Since I last updated Illustrator(in the past 2 months, including today), it is lagging with every stroke I try to move around and unite with other points, which I never experienced before and is very irritating because it takes such a long time to finally make my work the way I want it. Also, it is lagging when I have a couple of things that I worked on and I try to copy-paste them on another new file, it creates unnecessary selections that stays on the page and it all becomes black and I can't do anything about it but to close my previous work and work with just a single page. Not to mention that I had lost lost many times a half a day worth of work because is was just frozen all of a sudden, I didn't always saved my work on Drive.
Draw and design
Import and export
It has a lot of tips you can use for troubleshooting issues. Once you've gone through the steps, if you can't get it resolved you can post here with more information about your system, what you tried, and get further help.