During a Botani garrison invasion, if Spore Flowers end up being one of the recurring special events, one of them will inevitably “spawn” nowhere and cause all subsequent events to cease. This makes getting platinum an ordeal even at level 80 if you don’t have enough movement or ranged AoE abilities to keep hitting groups as they spawn.
This is a pretty long-standing bug, as it was doing this back when I first started farming up the invasion mounts in Shadowlands.