Can't change canvas orientation

I can’t change the canvas orientation between landscape or portrait. Changing it in the Inspector pallet has no effect. Neither has setting the Inspector to ‘Use Page Setup’, and changing it there.
I’m running Mojave 10.14.6 (18G103) and OmniGraffle 7.11.4 (v196.15 r337417).

Am I doing something wrong? If not, anyone else have this problem?

Just curious (because it is an interestingn puzzle):

  • So in the canvas inspector under Orientation, you have set “Page Setup”
  • What do you have under File -> Page Setup?

Aside: how do you like Mojave? I have not upgraded from 10.13. Some issues with other apps that don’t yet work with new MacOS.