Qt one signal to multi slot. And there are 2 connection type slots. Will there be any problems?

Question

Different classes and threads try to send one signal to two or more slots. There are two types of slots: queue and direct. Is it okay to use both DirectConnection and QueuedConnection for slots? ex)

B.cpp
A* a = A::sharedInstance();
connect(a, &A::signal, this,&B::slots, Qt::DirectConnection);

C.cpp
A* a = A::sharedInstance();
connect(a, &A::signal, this,&C::slots, Qt::DirectConnection);

D.cpp
A* a = A::sharedInstance();
connect(a, &A::signal, this,&D::slots);

The signal was transmitted only through QueuedConnection slots.