Why are there so many bugs?

Ever since Nani came out, when I play Showdown, the ranked icons get pushed to the side at the start. There's also a coin bug. ㅋㅋ It works fine after the update, though. Some people don't know that when you enter the Nani event zone, if you go to the Nani quests, it's not just Nani, you can keep scrolling sideways. Then regular brawler missions also show up.