The account should remain there once signed in on mintube even after minimizing the app.
After signing in to my account, I minimized the app and cleared it from recent apps, then I opened the app again and my account was logged out.
Launch the app.
Click on the account icon.
Click on sign in.
Sign in to your account.
Now minimize the app.
Clear the app from recents.
Now open the app again.
Error occurs, you're signed out.