We are sorry, you're having difficulties. Please help me with few details to understand your issue better.
Make and model of your device?
Application version?
We did try to replicate the behavior on our end, however, it is working fine. Make sure your application is updated. Reboot your device and then try. Try to reinstall the app once. For iOS Adobe Reader Mobile verion: 21.03.00
thanks for your reply.And I will answer your two questions.
1.The model of my phone is iPhone 12 pro.
2.The version of my application is 21.04.00 (20210415.143706).
And I saw some feedback on similar issues to me in the software's comment area.They said that when the software was upgraded from 21.03.00 to 21.04.00, we could not log in to the adobe account.Unfortunately I cannot download the previous version of the software. As of now, I still cannot log in to my account to use the subscription function.