It happened to me lot of times when the suggestions of clearing the board were not really related to the board minions at all.
for example I received 2 shadow-word-death spells for board of full 1/1 minions which is really useless and also duplicated spells
Dreamplanner Zephrys currently is not great like the old Zephyrs because of these 2 bugs: (random spells without calculating what we have on board at all) + (bug of duplicates)