Whenever the power goes out, and it happens a lot in my area the router seems to do a full factory reset and everything is lost. The username and password to sign in, SSIDs and passphrases have to be changed back every time the power is out.
Sorry to hear about the issue. From what I understand, the modem should not be going through a full factory reset each time you have a power outage. This has never happened to me. I have spoken to our Internet Technical Support department as well. They said the modem could be faulty and they recommend you exchange it. How many power outages are you having? That itself could be a concern.