The Storm Blade - progress glitch

So I was just going back and getting my missing skill point quests, and I went to act 9 to do the ruler of highgate quest. Looking at the map I saw I had four active quests: the lord's labyrinth, the ruler of highgate, fastis fortuna, and the storm blade. Selecting the storm blade as my active quest highlighted the vastiri desert zone as expected.
I completed the ruler of highgate and went back to town, giving the feather to Irasha. After this I realized the queen of the sands quest required first completing the storm blade. When I opened the map again clicking on the storm blade quest no longer highlighted the vastiri desert zone. The quest description now said "Quest Complete - You have delivered the Storm Blade to Petarus and Vanja. Talk to them for your reward." Despite the fact that I never did any part of the quest.
I went to the Vastiri Desert anyway and the quest was there as it should be, marked by the gold exclamation mark on the minimap. I did the fight and collected the storm blade as per usual. The quest progress didn't change from any of this. I went back to town and gave them the storm blade, which gave the appropriate dialogue but didn't open the quest reward pane. The dialogue option "Storm Blade Reward" did appear though, as it would if you backed out without selecting a reward. Selecting this opened the reward window and selecting my reward caused the quest to complete. I was then able to start the queen of the sands quest without issue.
I don't recall encountering this sort of glitch before, with a quest updating when it shouldn't. Hopefully it isn't a common issue because it was certainly confusing.