I only recently started using the plugin so I don't know when this broke, but standing on certain steep slopes causes the outline to render at the wrong height relative to the player.
There are several such spots that can be used for testing near Lumbridge's lum bridges.

I only recently started using the plugin so I don't know when this broke, but standing on certain steep slopes causes the outline to render at the wrong height relative to the player.
There are several such spots that can be used for testing near Lumbridge's lum bridges.