I have this strange behaviour with IVMS4500 on different smartphones and tablets. I installed 6 cams at this customer, I've forwarded all the right ports. Everything OK so far but after a while some cams are disconnecting. Sometimes only one and sometimes more than one and not always the same cams. It's always the password that's changed. When I correct the password, everything is ok again (for a while). The password is for all the cams the same and exists of 8 characters (2 letters and 6 numbers). I've not tried a different password yet. Anyone with this same problem?