The data appearing does not necessarily mean there isn't a network issue. Tableau has many high level maps local. You can test by zooming in on that server view to a lower level.
Check this KB for more help: Maps Do Not Display or Render Incompletely on Tableau Server | Tableau Software
I have experienced this issue several times and it has always gone back to network and Tableau Server administration. The correct ports have to be open on the network firewall of the maps will not render after publishing.
we also faced the same issue
and we are also on 10.5.2 desktop and server
did you find the root cause of it?
do you still have the issue? are you still in version 10.5 ?
everything in this poste is checked for us
This issue appears when we have high number of rows