Suggestion. Jake up your left side. give your tyre a hard shake.
if there is a lot of play, your wheel bearing might be the problem. or the ball on the arm
rear side arm got ball or not? i'm not sure.

and ya, undercarriage noise is dem cb

Rev when stationary at N got similar sound?
or only when moving around

sound inconsistent like going through bumps? or consistent frequency sound when moving
most likely less than rm300 can fix if you specifically want to fix that one problem only