On some of my site's pages I have a slideshow with its thumbnails below the menu from my A-Master page and with the slideshow contents to the right, like this: Jack Jensen Constructions
I can click on the Master menu buttons from most of my pages, but not ones with this layout. I suspect that it is because the frame around all of the slideshow objects overlaps with the Master menu, even though no true objects cover the menu. I've made sure to send the slideshow to the back of its page using the "arrange" feature and send the master menu to the front of its page, but that hasn't helped.
Let me know if you have any other ideas. I've used this layout for years and this hasn't been a problem until a recent update! Not sure which one though.
Seems that something is overlapping the buttons either on master or on that page.
Yes, the widget's "edit-all" border overlaps it. But that's not a real object that can be interacted with on the site; it's just a tool within Muse that, until recently, was ignored once the site went live.
Is there any way to tell the master's items that they should always be on top of whatever's on the pages?
Only if you place all master elements which should be on top are in one layer. the top layer on master.
On your pages nothing should be in that layer. Then it should do the job.