readDatagram() won't return the sender's address in Qt 5.10.0

I'm migrating my code from Qt 5.8.0 to Qt 5.10.0. But I find my code won't work any more.

In my situation, I send broadcast to 5 remote machines, then wait the answers (UDP) from them, and get their addresses from the UDP, so I use "readDatagram()". It works very well in Qt 5.8.0, but after migrated to Qt 5.10.0, it don't work anymore. The returned address and port both are wrong, address is empty, and "port" fixed to "1".

Platform: Win7 64bit, with Qt 5.10.0-VS2015-x86 precompiled library.