Thanks! Upon further examination, there seemed to be some cracking in the OEM sealant below the mounts. I slowly poured some water over them and seemingly revealed a few drops into that cavity. I applied some black silicone sealant to those; the roof rack bolts were plenty tight so I doubt it was coming from them. I only poured water over the cracks too, and was careful not to allow any to seep into the bolt area. See attached photo, I have to believe it’s letting water into the body.