When you enable the Dark appearance theme on macOS, the Illustrator File dialogs running input and output operations are still displayed in the Light theme.

Open the File input/output dialogs by running the following steps: 

• File > Open
• File > Export
• All File > Save options
• File > Place

GPU Sniffer and Safe Mode apps are docked separately

When you launch Illustrator, all launcher applications that run in the background, such as GPU Sniffer and Safe Mode, are docked in the dock bar along with Illustrator. macOS considers them as stand-alone applications and displays separate icons for them in the dock bar.

As a workaround, you can follow these steps to ensure that these applications don't appear on your dock: