test with a clean copy of quake (no other maps in baseq3) and confirm the textures are still missing. I've seen a few maps become broken with missing textures when certain other maps are present in the directory that conflict.

Superbad said everything correctly. I will just explain the reason step by step and give instructions.

What is the problem?
The server doesn't use map textures or shaders. The server only reads the .bsp file, from which it gets the map geometry. When you launch the client and connect to the server, your client only accepts the server's geometry rules and loads textures from your own .pk3 shader files. This means that the problem is not in the server part, and the map rotation file has nothing to do with it. Your problem is in the client side.

How to solve the problem?
So we're solving a client-side issue that doesn't involve map rotation, but rather a texture issue. You have some kind of map that breaks the textures of 1++ maps. How to find this map that is poisoning the life of your 1++ map? The easiest way to do this is by using the binary enumeration method.

In principle, with this approach, you can ask the waiter to cut the steak to save yourself time.