Can't access account from another device – Wunderlist: To-Do List & Tasks Review

I started using it on my iPad and it was great! User friendly and all that, but when I tried to switch it to my phone as well, I would sign in, verify who I was, and then be asked to sign in again. When I put in my information again, I was told the account already existed. I have tried turning off my phone, deleting and redownloading the app, and closing the app, but the same problem has been recurring. I can't use my phone; just my iPad. My account is a school account, and also, the button saying "can't get into my account" only lets you reset your password yet doesn't address my problem where I couldn't access my account. Definitely needs to be addressed, open to re-evaluating the app. When it works it really is great.
Review by zo2s on Wunderlist: To-Do List & Tasks.