I have only experienced this in the retake servers, but !guns only allows you to pick your pistol, but then doesn't actually set it. You either need to use !gun or gun to get the actual working menu. I assume this is because 2 weapon allocators are enabled in the plugins folder, or you added a custom one without disabling the retakes default allocator. If thats not the case, I'd recommend deleting all weapon allocators from the plugins folder, and re upload the right one to the plugins folder.