Hello,
I have the same problem. It has to do either with the password length or the characters in the password. OpenDNS allows a wide range of special characters and up to 256 character password length. The only way I could get this to work was by reducing the password length in OpenDNS and reducing the special characters. As a note, I use Keepass2 for my password generation. A 256-bit password with special characters, upper, lower, and numbers will create this issue.
Looking forward to a bug fix! Thanks!
