I'm just testing this with the September update, but it appears, the bug was still not fixed?
In the PBEM game that is suffering from the bug, it not only affects the Monumentality golden age, but also one of the beliefs of my religion: I had picked the belief that allows buying buildings in Campus and Theater districts with faith, and that is broken as well.
This game is still going to run for a couple of years, before it will be finished, so if we can't get a fix, I am not only looking at a wasted golden age (which is only temporary), but also at a wasted belief for the rest of the game...!
(Because of this we have currently paused the game -- since July... But the other players are now getting itchy and finally want to continue.)
PS: I tried the "ineedlegacyaccess" thing just now, but it does no longer work. Look like the current legacy version already contains the bug?