Make sure you are not selling anything on your retainers. Not part of a FC. And not in a residential zone. These are major things that can't be when transferring characters to another server.

Also, on Mogstation, it should have told you this. And other requirements that needs to be met upon applying for a server switch application. Furthermore, it doesn't matter if there is restrictions on character creation or not towards this. Transfers bypasses this. However, the server cannot be full at the time of transferring.
I hope this helps you, Amzz!