[REG 5.8->5.9]: QWebEngineProfile::defaultProfile() in combination with QProcess blocks application exit

QProcess. Application uses some helper process (also qt background app)

In my app Application class extends QAplication. i open some helper process which communicates with each other in Application constructor. Something like this:

proc->start(QString("%1/Proxifer").arg(dir.absolutePath()));
if(!proc->waitForStarted()) some code.
if(!proc->waitForReadyRead(5000)) some code
QByteArray p = proc->readAllStandardOutput(); 
// some code
 connect(proc, &QProcess::readyRead, [=](){

        QByteArray res = proc->readAll();

        some code

    });

In desctructor of Appliaction i close process and delete it, like this

>Application::~Application(){
    proc->close();
    delete proc;
}

Application blocks on proc->close() and didnt close. if i remove (proc->close()) application will close but with 5-10 sec delay.

This code works perfect in 5.8

Debugging shows that it stops on step proc->close() (see attachment)