Netbeans platform apps processes not properly caught at IDE shutdown?

[Guy_Daniel]

Yes, I have seen/am working on tracking down why netbeans is exhibiting this 
behavior also.
With version 12u1 I found it was linked to having JFX embedded with the JDK.
I could create a vanilla RCP project, run it on something like AdoptOpen JDK 
v11 and it would shut down fine.
Once I switched to Zulu JDK v11 with JFX embedded, it would not shut down.
I am also having the same issue with v14rc1 and the oracle jdk v17, but am also 
having trouble creating a vanilla RCP project with v14rc1.
 It's a work in progress for me.