I've noticed similar problems particularly when connecting with wifi. When you connect to a different network, if the dns address for your emm server needs to change to the local network address, the container did not update to the new ip address unless you kill container and open it again. An update to the server and client was supposed to fix this problem. In our case it did fix it. We do still have problems if a user changes his password, the battery will drain fast until the password is updated on the mobile device. Maybe if your AD account has logon restricted hours, it might fail to authenticate and drain the battery faster, I don't know.