QProcess doesn't finish after Ctrl-Z + BG on Linux

I am using Qt5.10 and RedHat Enterprise Linux 8.6

My application starts a child QProcess to do some work when a button is clicked.
Things work fine except when I do the following
Invoke the application in a Linux terminal
Suspend it using Ctrl+Z
Put it in background (bg)
Now when I click the button, I can see the QProcess get started but it never emits a finished signal.
When I run "ps", its shows that process as <defunct>

I am able to reproduce this using a simple test Qt application (see attachment)
It contains a button which when clicked starts a QProcess that runs the "sleep 1" command.
Here is what I see
Invoke test application
Ctrl-Z
bg
Press button
Things work fine (Get both started and finished signals)

Invoke test application
Press button
Things work fine (Get both started and finished signals)
Ctrl-Z
bg
Press button
Things don't work anymore (Get started signal but no finished signal!!!)