Eclipse Memory Analyzer does not show java processes

Having some java applications, which are just compatible with JDK8, I set my environment variable %JAVA_HOME% to the JDK8 path. Furthermore I would like to analyze memory leaks using Eclipse Memory Analyszer Tool (MAT) within these applications.

So i have downloaded AdoptiumJDK17, installed it, but did not set JAVA_HOME for this JDK. For starting MAT I have used the -vm Parameter for setting JDK17 in the ini-file. MAT is starting fine, but File -> Acquire Head Dump does not show any java.exe running with JDK8 in the background.

Is there any possibility to find these processes?