Your problem is caused by one simple thing: There is no Navigation Mesh in the Robot spawns, so the gamemode spawns all the bots on the nearest possible mesh (in your case, the Tank entrance)
You probably ran a nav_generate and since the spawns are in no way connected to the surrounding geometry, the generator ignored the spawns alltogether. You can still get a mesh there by marking them walkable (nav_edit 1, nav_mark_walkable on the ground in the Robot spawns, nav_generate_incremental so you don't replace your existing nav mesh with the ones you're about to generate in the Robot spawn)