Sagemcom modem wont let me change wireless channel or change any wireless > advanced settings

[Rev]

When I try to change my wireless channel to any channel number the screen acts as though I don't have permission to change settings. The same thing for anything else under the Wireless > Advanced section. If I change any other settings in this tab the 'apply/save' button remains greyed as though it has not realised anything has been changed. Below are pictures which illustrate the exact sequence of mouse clicks and show my problem.

TLDR; how do I change my advanced settings on my modem? I can access them, but no changes are kept.

http://puu.sh/rGqOu/7612311fd3.png

^ This shows default setting. 

http://puu.sh/rGqwr/4d9ccc3330.png

^ This shows the drop down menu when opening to change channel.

http://puu.sh/rGqzJ/31eec695dd.png

^This shows my mouse hovering over one number to click it and try change channel.

http://puu.sh/rGqDa/c004819c1b.png

^This shows exactly what happens after I have clicked channel (six in this case but happens with all channels). You can see how the drop down menu no longer has any text, it is no longer interactable, just a small blank box. 

http://puu.sh/rGqRD/82a5a24fa8.png

^Meanwhile the entire time my save button is greyed out and if I change any settings at all on this page, then click 'apply/save' then refresh the settings by leaving the page and coming back to it, it shows that all of my changes were not saved.

[caaf]

Apologies for not reading through the post (morning eye blur) but have you logged into the modem by any chance? 

[roseman]

I'm having the same issue, and I am logged in.

Did you end up getting any assistance?

[Guy]

Hey Rev. Once you select a channel, you'd need to press 'Apply and Save' right at the bottom of the screen for any changes to take affect. The last screenshot are options not supported by Optus so we wouldn't be able to help with them I'm afraid. 

[roseman]

Hi Guy,

I think Rev is having the same issue I am.

The problem is that when you select a new channel, it doesn't actually select a channel.  You end up with a drop down box with nothing in it, and it doesn't let you click Apply and Save.

[Guy]

I see. Does this happen on just the one browser or have you tried with a different one? 

[roseman]

Tried Chrome, Firefox and Edge, all have the same issue

[Gen_R]

Have you tried to do a reset on the modem, roseman? Sorry for any inconvenience caused, I can appreciate how frustrating this can be 😞 

[archbot]

Having the same issue, any solution?

[archbot]

Here is the error in the page when I tried to change the channel via the drop down:

wlcfgadv.html:1115 Uncaught TypeError: Cannot set property 'selected' of undefined
at loadChannelList (wlcfgadv.html:1115)
at onBandChange (wlcfgadv.html:1357)
at wl_recalc (wlcfgadv.html:1880)
at HTMLSelectElement.onchange (wlcfgadv.html:2271)
loadChannelList @ wlcfgadv.html:1115
onBandChange @ wlcfgadv.html:1357
wl_recalc @ wlcfgadv.html:1880
onchange @ wlcfgadv.html:2271