OSCSender and OSCReceiver ports

Hello. I created an OSС remote for the player. I used port 9001 for the OSCSender and the OSCReceiver for both ways. That is, in the player 9001 (OSS saver and OSCReceiver) and remote 9001 (OSCSaver and OSCReceiver). It works on Windows, Mac OS and Android. Now I’m trying to do remote App for iOS, but when I use the same port for the receiver and sender, the application crashes when trying to connect. If the ports for receiving and transmitting are different, everything works correctly. Is this how it should be, or am I doing something wrong? I will be grateful for the answer.