Sprout Master Not Counting + Sticker Confusion

I’ve been vanquishing volcano hoard zombies with Winter Greens repeatedly across both Adventure and Expeditions levels and the game isn’t registering it. 🥲

I’ve completed every level available and the sticker section of Intrepid Explorer still hasn’t unlocked ‘Famous Explorer”. What needs to be achieved to unlock it? It would be really helpful to know what is required for the stickers that are ‘Unavailable’. It would also be nice to know once the sticker is acquired — I have stickers that became available to me and no idea what I accomplished to unlock them anymore. 😅