https://www.polygon.com/2018/5/9/17336078/destiny-2-warmind-bug-heroic-strike-glory-milestone

The heroic strike playlist in Destiny 2 is currently bugged, with completed strikes not counting toward any player’s quest progress. This affects both the heroic strike weekly milestone and the new Warmind expansion’s glory exotic quest.

Bungie’s customer service Twitter account acknowledged the bug yesterday, saying that it’s currently investigating the problem.