I've personally not used the Wow Options system, but I would try to use the example in the wiki page below. If you were aiming to have a panel inside the wow options screen like several addons have done before .. you might want to see how close you are to the example in there.
https://warcraft.wiki.gg/wiki/Using_...s_Addons_panel
Take note of the known bug mentioned in the small print at the bottom.