CTRL-A not working?

I've been reading up on the work-arounds for the "Duplicate Map" issue. I cannot seem to make CTRL-A work. I need a specific breakdown of steps. Do I "highlight" the entire map? I find I have to move a tile to expose the bare underlay grid before I can do that, and once I highlight the entire map, the highlight window disappears and CTRL-A does not work. I can only transfer one tile at a time, and I'm trying to save some time if possible. Is there a specific set of steps that allow this work?

You should be able to go to the map layer,  ctrl-A to select everyone on that layer,  and ctrl-C to copy it... bounce over to a new map page, and ctrl-V to paste it.  It never drops it in the same exact place, so you do need to shift the whole mess around a bit afterwards

It is also recommended that you place a temporary marker/token in the top left corner before you select all and copy so that you can shift everything to it's proper place easier after you paste it (make sure you still have everything selected aka select all/control-a).