@rwgs this has been changed in firmware version 126.96.36.199 That has been superseded by follow-on trial versions, so, when one of the trial versions is approved as the next production version and released across the network, give your mixed passphrases another try.
@rwgs to request the trial firmware follow this link @CommunityHelps to navigate to the @CommunityHelps page when you are signed into the forum. On the right hand side of the page is a link titled "Send this user a private message". Use that link to navigate to the next message composition page. It will already be addressed.
Send that info to @CommunityHelps and you should see a reply later today or tomorrow.
When you're logged into the forum, watch for a number overlaying your avatar at the upper right hand corner. Follow the avatar link down to the message inbox to acknowledge the waiver that is required for the trial firmware. When that is acknowledged, you should see the firmware loaded later today or tomorrow. When you know that the firmware has been loaded, reboot or restart the modem. Don't run a factory reset as that will return the modem back to 188.8.131.52T2
On the other hand, if you find that the trial version is causing problems with your particular use of the modem, running a factory reset will result in the modem reverting back to the current production firmware version on the network followed by a reboot back into Gateway mode. You would have to reset the modem parameters once again unless you had previously created a backup file for that firmware version. That would allow you to start setting up the modem for the basic parameters only, then reload the backup file and reboot the modem to complete the backup file reload.
Is there a difference between CODA-4582 and CODA-4582U? Is this just an updated model?