@jsulm
I tried QChar to convert unicode and my problem solved. now qDebug prints the text correctly. 👌🏻
I also copied the readAllStandardOutput() to a QString and removed backslashes via remove("\x5C\x75").

You mean how to replace QTextCodec with QStringConverter? (QTextStream remains the same in Qt6 as in Qt5)
I've only used QStringConverter for the case shown above but there are more info for example here

@JKSH Thanks.

I would not bet that the bug is restricted to this encoding. But I will investigate this later and possibly report a bug to the correct venue.

Thanks again for your time and attention.