EDIT: Last update from May 4th fixed it. thanks !
After using the app in free mode for 2 weeks in offline mode without issues, I upgraded to the paid version.
Since then, I can’t start a new session in the course when offline (any of them: Learn new words, Difficult words, etc); the app stays stuck on loading the session (The “We are warning up the engine” screen). I have to switch to online for few seconds then only the session can start. As soon as I need to start a new one, I need to be online again.
I downloaded the offline package.
I tried to uninstall and reinstall too, the same issue still reproduce.