i replied to a post from 2 months ago, but tbh this seems like something that would be a really quick fix or at least to have an answer that it’s intended:
Blockquote https://us.forums.blizzard.com/en/hearthstone/en/hearthstone/t/246-known-issues/97048/187
to reiterate in short: getting a cursed treasure at the mystery node does not trigger task completion
edit 03/09/2023: just a quick update, i’ve tested all of the mystery node outcomes now and can confirm that only the cursed treasure does not progress the “visit a mystery node, boon, or spirit healer [#] times” tasks … all of the other mystery node outcomes – bomb, blue portal, sabotage, and bonus loot all progress these tasks