Any updates on this issue? On macOS 26.3.1 I'm still seeing the default insertion point, despite returning false from shouldDrawInsertionPoint in my subclass, when window becomes key. I'm forcing use of TextKit1. After a key press or mouse click the default insertion point disappears. My workaround is to listen for .didBecomeKeyNotification and perfor a dummy operation setSelectedRange(selectedRange()) in the notification handler.

I ran into this problem when reusing a Bundle Identifier in a new project. The above information helped me solve it, but cleaning out everything in com.apple.sharedfilelist/ seem a bit overkill as it would remove recent files from all applications. You could try using finder to delete just the file associated with your app. Either browse your way there, or run the following in a terminal: open ~/Library/Application\ Support/com.apple.sharedfilelist/ Locate the file named with your Bundle Identifier (e.g. org.you.AppName.sfl2) and trash it. Then run killall sharedfilelistd