MQTT WebSocket doesn't connect

When I use my code to connect to my MQTT server over WebSocket using QT 6.3.2, everything works perfectly.

But when I compiled the exact same code with QT 6.4.0, the connection to my MQTT server over websockets always timesout with no error messages.

There's no compiler errors.

If I compile for WebAssembly, everything works. I assume webassembly do not use any of the network and ssl libraries used by IOS & OSX, so I suspect something is wrong with the network and/or ssl libraries.

By the way, I also tested with the WebSocket MQTT example and I get the same issue. If I compile using version 6.3.2, the MQTT connection connects perfectly over websockets. If I compile the exact same code using version 6.4.0, the MQTT connection timesout.