A DESCRIPTION OF THE PROBLEM :
Currency.getInstance( Locale.getInstance( "ro", "RO", "" ) )
        .getSymbol( Locale.getInstance( "ro", "RO", "" ) )
result=RON, expected "lei"

There is no locale that will result with the expected currency symbol:
Stream.of(Locale.getAvailableLocales())
        .map( l->currency.getSymbol( l ) )
        .collect(toSet())
result = {HashSet@5442} size = 1
 0 = "RON"

Found a similar resolved issue for another currency in your bug db. As this was working in jdk 8, you should create some tests for symbols to prevent this kind of issues in the future.

REGRESSION : Last worked in version 8u201

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Currency.getInstance( Locale.getInstance( "ro", "RO", "" ) )
        .getSymbol( Locale.getInstance( "ro", "RO", "" ) )

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
"lei"
ACTUAL -
"RON"

---------- BEGIN SOURCE ----------
Currency.getInstance( Locale.getInstance( "ro", "RO", "" ) )
        .getSymbol( Locale.getInstance( "ro", "RO", "" ) )
---------- END SOURCE ----------

FREQUENCY : always