Illustrator saving, creating files, and opening files seems to be tied to an internet connection, and it really fails if the connection isn't strong/stable. And this was only an issue with Illustrator (found with 24.2.3 & 24.2.0) with Photoshop and Indesign continued to function normally.

For two weeks I began experiencing very slow saving, it being "not responsive" for about 10 minutes to save any file. I eventually found it was tied to my internet connection. I recently switched my home network to data from a mobile hotspot which works find but isn't always stable. So the saving issue wasn't happening all the time, but most of the time.

I eventually found that if I disabled my internet connection these operations, Saving, Opening, & creating files, began working normally again.

I created a video of this happening: https://youtu.be/eGULdnsanlI

This was originally posted in the community help forum: https://community.adobe.com/t5/illustrator/illustrator-2020-hangs-and-very-slow-when-saving-on-windows-10/m-p/11386076?page=1#M190428