Second app instance does not exit

Junology

Most appropriate sub-area of Processing 4?

PDE

Processing version

4.4.3 (portable)

Operating system

Linux (Ubuntu 20.04 x64)

Steps to reproduce this

"1. Download processing-4.4.3-linux-x64-portable.zip, extract it, and cd Processing/bin

./Processing & and wait for Processing to launch.
./Processing & again and wait for the second Processing IDE to launch.
Close both Processing windows.
ps | grep Processing and you'll see the second Processing process is still alive."

snippet

Additional context

I also observed the same happens for local build with Gradle.
The problem is not critical since Ctrl-C terminates it anyway, but it is a bit bothering when it happens.

Would you like to work on the issue?

No; I am not familier with Kotlin, sorry.