Dialog is not visible again when parent Window/ Frame is
hidden and shown again or made invisible and visible again

Compile and Run DialogTest.java

Click on the button, Hide. The Frame and Dialog will be hidden. After sometime the Frame is showed, but the Dialog is not shown again by default.

Click on Invisible button. The Frame and Dialog will be made invisible. After sometime Frame is made visible, but the Dialog is not made visible again by default.

Click on Minimize button. The Frame and Dialog will be minimized and both Frame and Dialog is set to Normal by default. Its working fine.

As per docs

When the owner window of a visible dialog is hidden or
minimized, the dialog will automatically be hidden from
the user. When the owner window is subsequently re-opened,
then the dialog is made visible to the user again.

This is occuring in all platforms