I don't have a ETA
Just to let you know, I've figured a temporary work around in order to call the lightbox on the Mobile Forum part of the website.
I created a link-page call Menu and used it as a link to a lightbox. (It's just not too obvious with it being tucked away in a menu).
Ideally, the problem would be solved if I could just have a floating button to rest above the WIX Forum to just call the lightbox to make it more obvious.
I've kept the previous code in place, so when a fix is done I'm guessing it will just start to work properly.
Many thanks for your time and effort
Thank you for the update!