The internal SHAKE256 class fails the NIST CAVP test when n reaches 137. The following program succeeds in the 1st check but fails the 2nd one.

import sun.security.provider.SHAKE256;

import java.util.Arrays;
import java.util.HexFormat;

public class A2 {
    public static void main(String[] args) throws Exception {
        //https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Algorithm-Validation-Program/documents/sha3/shakebytetestvectors.zip
        //SHAKE256VariableOut.rsp:
        //3380: COUNT = 674
        //3381: Outputlen = 1088
        //3382: Msg = 6ae23f058f0f2264a18cd609acc26dd4dbc00f5c3ee9e13ecaea2bb5a2f0bb6b
        //3383: Output = b9b92544fb25cfe4ec6fe437d8da2bbe00f7bdaface3de97b8775a44d753c3adca3f7c6f183cc8647e229070439aa9539ae1f8f13470c9d3527fffdeef6c94f9f0520ff0c1ba8b16e16014e1af43ac6d94cb7929188cce9d7b02f81a2746f52ba16988e5f6d93298d778dfe05ea0ef256ae3728643ce3e29c794a0370e9ca6a8bf3e7a41e8677067
        //3384:
        //3385: COUNT = 675
        //3386: Outputlen = 1096
        //3387: Msg = 8d8001e2c096f1b88e7c9224a086efd4797fbf74a8033a2d422a2b6b8f6747e4
        //3388: Output = 2e975f6a8a14f0704d51b13667d8195c219f71e6345696c49fa4b9d08e9225d3d39393425152c97e71dd24601c11abcfa0f12f53c680bd3ae757b8134a9c10d429615869217fdd5885c4db174985703a6d6de94a667eac3023443a8337ae1bc601b76d7d38ec3c34463105f0d3949d78e562a039e4469548b609395de5a4fd43c46ca9fd6ee29ada5e
        var s = new SHAKE256(1088/8);
        var msg = HexFormat.of().parseHex("6ae23f058f0f2264a18cd609acc26dd4dbc00f5c3ee9e13ecaea2bb5a2f0bb6b");
        var output = HexFormat.of().parseHex("b9b92544fb25cfe4ec6fe437d8da2bbe00f7bdaface3de97b8775a44d753c3adca3f7c6f183cc8647e229070439aa9539ae1f8f13470c9d3527fffdeef6c94f9f0520ff0c1ba8b16e16014e1af43ac6d94cb7929188cce9d7b02f81a2746f52ba16988e5f6d93298d778dfe05ea0ef256ae3728643ce3e29c794a0370e9ca6a8bf3e7a41e8677067");
        s.update(msg, 0, msg.length);
        if (!Arrays.equals(s.digest(), output)) {
            throw new RuntimeException();
        }
        s = new SHAKE256(1096/8);
        msg = HexFormat.of().parseHex("8d8001e2c096f1b88e7c9224a086efd4797fbf74a8033a2d422a2b6b8f6747e4");
        output = HexFormat.of().parseHex("2e975f6a8a14f0704d51b13667d8195c219f71e6345696c49fa4b9d08e9225d3d39393425152c97e71dd24601c11abcfa0f12f53c680bd3ae757b8134a9c10d429615869217fdd5885c4db174985703a6d6de94a667eac3023443a8337ae1bc601b76d7d38ec3c34463105f0d3949d78e562a039e4469548b609395de5a4fd43c46ca9fd6ee29ada5e");
        s.update(msg, 0, msg.length);
        if (!Arrays.equals(s.digest(), output)) {
            throw new RuntimeException();
        }
    }
}

BTW, when n > 200, the state buffer in SHA3.java does not have enough bytes and the last line of implDigest() throws an exception. It probably needs to squeeze multiple times to fullfill the output.