See my comments below:
You said: I've tried to copy/monitor in some walls from the Architectural Revit model (just like in the video) rather than just monitor. They import and I get the warning about overlapping etc..
I said: If the link and host have that same wall in the same place and you Copy/Monitor in the host file you will now have 2 walls in exactly the same location. The whole idea is to not have the wall in the host and copy it in from the link. This way if the wall moves down the road Revit will know and tell you.
You said: but they are Just not there.
I said: Sorry, you lost me on the above, can you expand?
You said: I've tried unhiding and they are not their either, I tried fixing visibility graphics to show all of the architectural items.
I said: so it sounds like you are clicking on the correct link and nothing is hidden.
You said: Does it matter that these Architectural models are central models?
I said: By central model do you mean you are working in a file that has Worksharing enabled? Or, you opened the Central File and started working in it. In ether case I don't believe it will make a difference. However, you should never work directly in the Central File.
As a matter of interest if you create two files (Host and Link). In Link add a few Grids and number them L1, L2, etc. and add few walls. In Host, link in Link file and then Copy/Monitor the Grids and the Walls and click the Finish button (just like the video), save and close the file. If you open Link and move one Grid and one wall and save, close. Now reopen the Host file and you get a Coordination Message, what happens? The expectation is that whatever you moved in the Link file should have moved in the Host. This is how its supposed to work. If you are getting different results we may have to take his case internally and I will arrange a time where we can do a TeamViewer Session. If however its working as expected I'm left wondering what went wrong in your file. I guess if you Stop Monitoring everything and start again we may be able to narrow down the issue.
Thank you