ADDITIONAL SYSTEM INFORMATION :
Windows 11 with latest updates

C:\>javac --version
javac 21.0.1

C:\>java --version
openjdk 21.0.1 2023-10-17 LTS
OpenJDK Runtime Environment Microsoft-8526870 (build 21.0.1+12-LTS)
OpenJDK 64-Bit Server VM Microsoft-8526870 (build 21.0.1+12-LTS, mixed mode, sharing)


A DESCRIPTION OF THE PROBLEM :
Pattern-matching executes a `case` different from the expected one.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
javac --enable-preview -source 21 Test.java
java --enable-preview Test


---------- BEGIN SOURCE ----------
abstract class FuLiteral {}
class FuLiteralNull extends FuLiteral {}
class FuLiteralFalse extends FuLiteral {}
class FuLiteralTrue extends FuLiteral {}

public class Test
{
public static void main()
{
final FuLiteral left = new FuLiteralFalse();
final FuLiteral right = new FuLiteralTrue();
switch (left) {
case FuLiteralNull _ when right instanceof FuLiteralNull:
case FuLiteralFalse _ when right instanceof FuLiteralFalse:
case FuLiteralTrue _ when right instanceof FuLiteralTrue:
System.out.println("BAD");
break;
case FuLiteralFalse _ when right instanceof FuLiteralTrue: // <-- expected
case FuLiteralTrue _ when right instanceof FuLiteralFalse:
System.out.println("OK");
break;
default:
break;
}
}
}

---------- END SOURCE ----------

FREQUENCY : always