If the maps do not load at all, it sounds like the Tableau Server may not have access to download the maps or could be blocked because of Run As User permissions. What does F12 network console tab show in a web browser? Are there any 401s to your map server? You could also try experimenting with client/server side rendering.
Testing with the URL Parameter
To test server-side rendering on a session basis, type
?:render=falseat the end of the view's URL. For example:
If client-side rendering is disabled on Tableau Server, enter
?:render=trueto enable it for the session:
Hope this helps!
Thanks for your reply. I already tried your suggestions, but to no avail. As I mentioned in my post, a very simple map with very little data behind it renders fine. Moreover, the URL to the maps, be it Tableau or MapBox, are accessible from both the Tableau server and the client PCs. Tableau desktop and server run on the same machine, maps render ok in the desktop but even in a web browser on the server they don't show...