I think your infrastructure version is very old. Also, as far as I remember, a solution was published for this problem in 2017, I think. The solution was part of the client, specifically the zone file, and also a solution that was being implemented in the server source and client.
But there is a solution that might work for you. Drag the zone files and also the textureset files for the tower and the problem might be solved, but you have to work a little to know the name of the map file, and this will require you to know the name from the map index on the server.
Note: I am trying to help you as much as I can and as far as I remember because it is a very old problem.