Got the following to replies:
When asked if the app would logout an user every 30 days:
No, the app will not log the user account out every 30 days. Usually if the app hasn't been login for more than 30 days, this noticifation will pop out. It seems that there is something wrong in the app so that you received the notification even you are using the app everyday. I forwarded this information to our engineers and ensure you that we take it seriously and this issue will be resolved as soon as possible.
Then I asked for a plain statement if there was a password leak
No, rest assured that your password was not disclosed. The message we sent is not correct and it will be improved in the next version. If you still worry about this issue, it is recommended to change your password.
It's still not clear to me what really happened, but I'm stopping this thread with them.