*.replace(); does not work on Arduino Uno Wifi Rev. 2

[oppaernst]

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Hello,

it is not possible for me to get proper results for the following code on all of my Arduino Uno Wifi Rev. 2:

String currentLine = "%2216%22,%20%2217%22";

void setup()
{
  Serial.begin(115200);
  Serial.println(currentLine);
  currentLine.replace("%22","");
  Serial.println(currentLine); 
  currentLine.replace("%20","");
  Serial.println(currentLine);  
  Serial.println("The result should be 16,17 but it is not.");
}

void loop()
{
}

The serial monitor gives me:

%2216%22,%20%2217%22
%2216%22,%20%2217%22
%2216%22,%2217%22

The result (the last Serial.println(currentLine);) should be 16,17 but it is not.

Is there any workaround for this problem?

Kind regards