x-windows-iso2022jp converter encode some characters differently between JDK 8 and JDK 11.
Since JDK 7 works as expected it is a regression issue in JDK 8.

//JDK 8
$ java -showversion TestEncodeProg
java version "1.8.0_211"
Java(TM) SE Runtime Environment (build 1.8.0_211-b08)
Java HotSpot(TM) 64-Bit Server VM (build 25.211-b08, mixed mode)

JIS String MS932 Unicode(codepoint)
0x224C � 0x3F 0xFFFD
0x225D � 0x3F 0xFFFD
0x2265 � 0x3F 0xFFFD
0x2269 � 0x3F 0xFFFD
0x2D70 � 0x3F 0xFFFD
0x2D71 � 0x3F 0xFFFD
0x2D77 � 0x3F 0xFFFD
0x2D7A � 0x3F 0xFFFD
0x2D7B � 0x3F 0xFFFD
0x2D7C � 0x3F 0xFFFD

//JDK 11
$ java -showversion TestEncodeProg
java version "11.0.3" 2019-04-16 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.3+12-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.3+12-LTS, mixed mode)

JIS String MS932 Unicode(codepoint)
0x224C ￢ 0x81CA 0xFFE2
0x225D ⊥ 0x81DB 0x22A5
0x2265 √ 0x81E3 0x221A
0x2269 ∫ 0x81E7 0x222B
0x2D70 ≒ 0x81E0 0x2252
0x2D71 ≡ 0x81DF 0x2261
0x2D77 ∠ 0x81DA 0x2220
0x2D7A ∵ 0x81E6 0x2235
0x2D7B ∩ 0x81BF 0x2229
0x2D7C ∪ 0x81BE 0x222A

//JDK 7
$ java -showversion TestEncodeProg
java version "1.7.0_221"
Java(TM) SE Runtime Environment (build 1.7.0_221-b08)
Java HotSpot(TM) 64-Bit Server VM (build 24.221-b08, mixed mode)

JIS String MS932 Unicode(codepoint)
0x224C ￢ 0x81CA 0xFFE2
0x225D ⊥ 0x81DB 0x22A5
0x2265 √ 0x81E3 0x221A
0x2269 ∫ 0x81E7 0x222B
0x2D70 ≒ 0x81E0 0x2252
0x2D71 ≡ 0x81DF 0x2261
0x2D77 ∠ 0x81DA 0x2220
0x2D7A ∵ 0x81E6 0x2235
0x2D7B ∩ 0x81BF 0x2229
0x2D7C ∪ 0x81BE 0x222A