If the Special Day that appears on your KakaoTalk profile doesn't match up, please check the below information.
1. If you logout and log back in to your Between account, the link to your KakaoTalk account is terminated. If you logged out at some point, please sync your Special Day with your KakaoTalk again.
2. The Special Day on your KakaoTalk profile doesn't update automatically. Please run the Between app first and then open your KakaoTalk app.
3. Go to (iOS) device settings and check if the 'Background App Refresh' is on (Settings > Between > Background App Refresh).
※Please disable your Special Day link before deleting your KakaoTalk account.