[macOS only] This issue exists for the Korean, Turkish, Hungarian, French, French Canadian, French Maroc, and Portuguese Brazilian locales.
Issue: When you deselect the Open Document as Tabs option in the Preference > User Interface dialog and create a new document using the options provided on the Home screen, the newly-created document hides behind Illustrator. This issue can be seen if you press Command+N or click the Create New button on the Home screen.
However, if you create a new document using the File > Create menu, this issue does not occur.
Workaround: Open a new document using the File > Create menu.
Issue: When you select a font as favorite through fonts.adobe.com, it takes a long time to reflect the changes in the Favorites filter on the Find More tab of the Character panel (Window > Type > Character).
Workaround: In some cases, changes are available if you quit Illustrator, reopen it, and then open the Character panel.