With the attached ICC profile, the following code:

QFile file("/path/to/cali2-BenQ_SW271_24-02-28.icc");
if (!file.open(QIODevice::ReadOnly)) return;
QColorSpace colorSpace = QColorSpace::fromIccProfile(file.readAll());
file.close();
qDebug() << colorSpace.isValid(); 

Reports an invalid color space and writes the warning:

qt.gui.icc: fromIccProfile: failed minimal tag size sanity

The ICC profile contains a tag with the signature "DDPS" whose element size is 9. The corresponding data has type signature "text", which if I understand the ICC specification correctly, would be valid because it just needs the standard 8 byte intro that all tag data has, plus at least one for the text's null terminator. It seems that the tag size sanity check is being overly aggressive.