In JMeter JSR 233 element There's an Edit option in language Combo box,
If you leave empty it chooses by default groovy, but if you write engine name it's error prone and irrelevant because according to previous question
drop down is being populated on-the-fly using
ScriptEngineManager.getEngineFactories()
method which performs discovery of available scripting engines in JMeter Classpath.
So if you can choose in drop down only relevant engines why you need to input manually different (not working) engines?
Is it a bug of JMeter? or is there a special reason/usage?