Can also confirm that this is still bugged. Playing my reaper when I managed to kill a Treasure Mushroom, and the Spore unlocks for the Chronomancer … Second time killing the Treasure Mushroom nothing drops.
This is so annoying. This combined with the no rewards from map completion has just killed this achieve for me.
—Edit—
I don’t agree with this method or bug of having to get a new Spore for each class, but after a little research and playing with this a little more. I have discovered the following;
1: When gaining an Invisible Mushroom Spore it will apply to the elite specs you have unlocked in alphabetical order. Mine for example was Chrono -> DD-> DH -> Reaper
2: You can only gain the Spore once from each Treasure Mushroom per day.
The folks over on Reddit have kindly put together a rough idea of the spawn locations.
