I've also noticed that this board, though it is checked as "Is Sprint" sometimes appears with estimates on tasks in sprint/workboard view and the burndown chart feature (icon) on the side nav and sometimes those things disappear.
No idea how to reproduce this behavior, seems random :-(
This is confusing for sure. The problem is that there are two completely independent "contexts" for the board. For example, if you click on the project tag it puts you in the Sprint "context", meaning that what is shown is controlled by the Sprint extension. However, the default Phabricator projects "context" still exists and this is completely free of any interaction with the Sprint extension. This is accessed if you click on the Project name link, or if you are in the default Project Profile and click on the board icon on the navigation bar.
The default is still present for several reasons, and the main one is that if something is wrong with the Sprint extension, people will always be able to see a board view through the normal projects context. There is one sure way to know if you are in the Sprint context and that is if the icon bar shows the flame icon. If it is not there, then the way to get back is to select the "View Sprint Board" or "View Burndown Chart" from the Action Menu in the Project profile.
It is a bit of a dilemma to solve, because I would not really advise forcing all board routes through the Sprint context at least until when or if the Sprint extension reaches a more stable level. But at the same time, this would make things a lot more clear.
Ah, well that makes sense! Many thanks for the explanation Christopher.
I agree that there could be better ways to arrange various UI elements in Phab to prevent this confusion (but I have no good ideas to offer on this front right now :-)). In the meantime, I think I'll add a note to the documentation here to explain this and hopefully prevent some further confusion: https://www.mediawiki.org/wiki/Phabricator/Project_management#Boards