I cleaned both surfaces thoroughly

Gasket was bought from Max BMW. I assume it’s the factory gasket.

I’ve got a leak from right side valve cover. I’ve replaced the gasket with a new one. I believe previous owner replaced valve cover with aftermarket one since there isn’t a bmw part number on the inside. I’m out of ideas. Not sure what else to do.

I was just given a 2012 RT by my dad who has become too old to ride. I’ve been riding an RT for work since 2020.