I've always been able to switch between separate windows in the Terminal app, using e.g. Command-2
to go to the second window.
I upgraded to macOS 10.13.1 last night, and now none of the Command-<digit>
shortcuts work.
How come?
No. They just changed them a little. Now, if you are in, say, Tab 1, you can switch to Tab 2, with Command + Option + 2
and then it works the opposite way. I hope this helped.
Edit: For me the Command + {number}
does work. I'm also on the same OS.