The Big5-HKSCS character set converter incorrectly maps U+23FF0 to the sequence 8E6A and U+25D20 to FDD8. This was a bug in the Unihan database up until Unicode version 4.0.1, which switched the mappings. Thus U+23FF0 should map to FDD8 and U+25D20 should map to 8E6A. From the 4.0.1 version of the Unihan database: U+23FF0 kHKSCS FDD8 U+25D20 kHKSCS 8E6A The 3.2.0 version still has: U+23FF0 kHKSCS 8E6A U+25D20 kHKSCS FDD8
Fixed by f22bc48