I encounter purple vocab cards in my lessons before seeing the pink cards that are referenced by the purple. In the example below I haven’t learned Service before studying role. Is it a bug? It isn’t every time, but I notice the more common pattern is to encounter them in order: radical —> pink card —> purple card.
I’ve also encountered recently with 東: several pink card/purple cards using 東 —> (a couple weeks) —> 東 radical.
Radical cards after the kanji is pretty normal, sometimes (especially in the later levels) they want to teach the kanji as the sum of its components when explaining the kanji but use it as a block in later kanji so.they don’t need to make mnemonics with 7 or 8 components.
Kanji cards after vocab are less common - usually this is the result of Wanikani updating the content and moving stuff around.