That’s bizarre. The other pages say there are six levels, which I believe is currently true.
http://www.sc-top.org.tw/english/RD/test4.php
http://www.sc-top.org.tw/picture/Conversion_R_E.png
https://www.sc-top.org.tw/english/WR/over.php#wr04
https://www.sc-top.org.tw/english/SP/test1.php#sp04
The old HSK had 10 levels iirc, but they changed it about a decade ago.