Open multiple PDFs in same window no longer works

[mashby]

I just installed Acrobat Reader DC (20.009.20065). This setting under Preferences\General doesn't work.

Even after closing Acrobat and relaunching it, any time I open a PDF, and then via the Window menu and New Window, it opens an entirely new session of Acrobat.

[Bernd Alheit]

This is correct. The function "New Window" opens a new window.

[try67]

What did you expect to happen when you used that command?