Shortcut keys not working in “New Folder” dialog within Save As dialog is tracked with this issue – https://illustrator.uservoice.com/forums/601447/suggestions/39374122
Overall issue of shortcut keys not working in Save As dialog is fixed in Illustrator version 24.0.1
An error occurred while saving the commentJustin commented
When you create a new folder on a Mac in Illustrator 2021, you cannot Cmd + c then Cmd + v in the folder name.
Illustrator team is working on a fix for this issue