Advanced Control Custom CSS Menu Element is not appearing

I’m working on a single page site with anchor links / IDs to various sections. We have done this in a few other sites, using the advanced controls to set an ID for that element. However, that advanced control seems to have vanished. I tried looking for it on columns, rows, and blocks, and it is not appearing. https://www.boldgrid.com/support/page-builder/advanced-controls/

I logged in to other sites we have used it on and while the menus still function, the Advanced Menu does not show the missing item.

Custom CSS – Enter Custom Classes or a CSS ID for the element

Do you have any insights as to what is happening? I’ve tried both Chrome and Firefox and not seeing it in either…though for a moment this morning I DID see it when I went to a block and so went to the one where I want to set an ID and it no longer was visible. Went back to the one where I had just 3 min before seen it and it was gone. I think there may be a javascript error?

When inspecting the page, the CSS shows that the Menu item is in the code, however, it is not visible. I’ve placed two screen captures illustrating this in a dropbox folder https://www.dropbox.com/sh/5nqfeqdb2tyel11/AABGiWfHawHwpnakxWwOoMsTa?dl=0