Answer by Liyun Zhang - MSFT for DrawerLayout must be measured with MeasureSpec.EXACTLY error only in Android MAUI

I created a new project to test the code you provided and reproduced this issue. Even though the navigation worked well on the Windows and iOS, I suggest you navigate from shell to another shell by setting MainPage. Such as:

private void OnCounterClicked(Object sender, EventArgs e){     App.Current.MainPage = new NewTabbedPage();}

If you don't want to use new(), you can use the Dependency injection for it.

And for the DrawerLayout must be measured with MeasureSpec.EXACTLY error, you can report it as a new issue on the github repo.