I just started playing a map where I start with 6 territories, but for some reason I can only deploy to 2 of those specific territories, and none of the other four. This isn't some special scenario map either--it's a custom level I created a couple years back and I know was able to deploy to any territories I liked back then. Also, only those two territories are able to even attack.

It's been about a year since I played Warzone--are these changes that were made to the game or something?

Are you sure they're your territories? Try using the magnifying lens in the top left to get info and confirm they're owned by you.

The magnifying lense worked on those two territories and none of my other ones, but it did work on some enemy territories to show where they could send their armies to. But with the vast majority of territories I use the lense on nothing comes up at all, whether mine, neutral or enemy. I click but it's as though I hadn't clicked at all. This is really strange. I've played Warlight/Warzone on and off for years but never seen anything like this before.