QODBC: QSqlQuery::isNull returns false for SELECT NULL

#include <QtSql/QSqlDatabase>
#include <QtSql/QSqlQuery>
#include <QtCore/QVariant>
#include <QtCore/QDebug>

int main() {
    auto db = QSqlDatabase::addDatabase("QODBC");
    for (auto cs : { "Driver={PostgreSQL Unicode};          ;Server=127.0.0.1;   ;Database=POLL_TEST",
                     "Driver={ODBC Driver 18 for SQL Server};Server=192.168.1.249;Database=POLL_TEST;TrustServerCertificate=YES" }) {
        db.setDatabaseName(cs);
        if (!db.open("PSO_login", "123")) continue;
        QSqlQuery qry("SELECT NULL, 1234", db);
        if (!qry.next()) continue;
        auto v0 = qry.value(0), v1 = qry.value(1); //doc says "call isNull after data access"
        if(v0.toInt() == 0 && v1.toInt() == 1234)
            qInfo() << QString(cs).split(';').first() << ((qry.isNull(0) && !qry.isNull(1)) ? ": PASSED" : ": FAILED");
    }
}