So just figured out the simplest thing...
I plug my USB mouse into the stock Samsung s8 USB adapter to the phone.. and I get a mouse.
I open up runescape and the mouse doesn't work... can I fix this any advice?
Jagex are a useless company, You shouldn't expect them to posses the know how to implement this. bet you if they tried users would probably get picked up by their anti bot detection or something.