Which new functional features? I'm not aware of any since Java 8 and those were pretty feeble. Java still doesn't offer Regex without having to escape metacharacters. That's how primitive it still is.
And these are only language level changes, the platform has expanded insanely significantly, but that also benefits clojure greatly (which is a good thing, it’s no competition)
I am still early in my career. I'm still discovering stuff for first time. I've also found that I am much more likely to use streams, lambdas, Optional and predicates in code compared to my more experienced colleagues. My functions tend to be pure more often, code has more interfaces than inheritance and generally more unit testable. One of the surprising moments was learning Elixir and realising I'm already doing the pipe thing in Java with Optional.map().
Java will never shed its OO skin but it is starting to grow FP muscles in the right places.
Collection factory methods https://openjdk.org/jeps/269
Stream API improvements https://www.javatpoint.com/java-9-stream-api-improvement
Honorable mention since not strictly functional, but makes code clearer and integrates well with functional patterns: pattern matching for switch statements https://openjdk.org/jeps/427