jsse.enableFFDHEExtension is described in a lot of JDK security docs. That property doesn't actually exist in the src code base. It should be jsse.enableFFDHE

some docs:
https://docs.oracle.com/en/java/javase/14/security/java-secure-socket-extension-jsse-reference-guide.html#GUID-460C3E5A-A373-4742-9E84-EB42A7A3C363

https://docs.oracle.com/en/java/javase/11/security/java-secure-socket-extension-jsse-reference-guide.html#GUID-460C3E5A-A373-4742-9E84-EB42A7A3C363

https://www.oracle.com/java/technologies/javase/9all-relnotes.html