Problems with readStringUntil

Hello, i'm trying to use the function readStringUntil('\r') to store a in a String variable a message received from a tcp client and perform some actions... When i call

String str = client.readStringUntil('\r');
Serial.println(str);

some seconds later i receive a strange reply in Serial monitor.

This is what i received

⸮⸮⸮⸮

if in the tcp client i wrote something, i receive, only for the first print these carachters and then the string i put in the tcp client.

Any idea?

looks like different baudrates between what is defined in the

Serial.begin();

command

and the actual baudrate that the serial monitor is adjusted to.

best regards Stefan

Thanks, i found that the problem is in the app that i'm using to test the script. An app for iOS that send a connection confirmation any time i connect to the socket.

Use of another app solves the problem.

Thanks anyway.

Regards