Today while beta testing a mansion, I paused while I had the map up and I couldn't select suspend. I had to resume, get rid of the map and pause again to be able to suspend. I had made a change to the mansion which is why I was needing to suspend.

One has never been able to suspend the game when viewing the map!

I've been wondering too, it's a bit curious indeed. Not even annoying, just eyebrow-raising  :-?

There are certain situations where, from a programming perspective, it would be extremely difficult (if not impossible) to allow the game to suspend. Since those situations are easily avoided (i.e. dismiss the map screen), it's a nice solution to just require the right conditions for suspend to happen.