Mine recently developed same problem. It's definetely a windshield trim. So far best solution is to spay littl windshield washing fluid while driving. It shuts it down completely.Guess it gets into gap and prevents molding from vibrating. For how long depends on how hot and dry it is outside.

92 SR, 285/75R16 Yoko MT ARB locker GAST compressor AirLift 1000 MM10500 Snorkel custom rear bumper
02 Montero LS died protecting the master
08 PowerWagon (stock!)