Hello - I have this issue on my iPad too. It keeps saying "Try later...". I tried deleting and reinstalling as well as changing my password and attempting again, but none of that worked.
My question is how long do you think is needed to see an improvement? With the test changing in the summer I feel like time is limited. Also, how much studying per day do you think is adequate?
You have to use the old format instead of the new one, unfortunately. I sent 7sage an email about changing this since the old format doesn't have as many analytics