EDIT: I haven't seen your post in the meantime. All good, thanks!
Hi,
Thank you for your staying with us!
This maybe a session related issue on your mobile device.
Can you please try going to the Profiles and click your account again?
Does it open "Files" screen or perhaps open login screen (in such case, can you please login to the app?)
You can also try visit Sessions (as on the attached screenshot) to see on what devices you're logged in. If this screen doesn't open properly, then it means that for some reason your session has expired.
We're still improving the auth system so the rare occurrence of "logout" doesn't happen.
I hope that helps a bit! (edited)