Thanks again Fran. I pinpointed the problem to props not being passed down. pageStack prop doesn’t seem to be going down from navigator to the page itself, it is always undefined on sub components. I was able to go around it using a computed property (deriving from a global pageStack) on each page but it’s less than ideal.
With regards to pageStack woe itself:
When I use this,
this.pageStack = ; this.pageStack.push(page);
the back button keeps showing up even though clearly there is only 1 page in pageStack.
When I use this:
this.pageStack.length = 1; this.pageStack = page;
back button behaves as it should, i.e. not showing up.