It might be an issue with manufacturing tolerances of either Panasonic or Nauticam. Here is a photo of the Olympus 60mm focus gear contacting the nose on my GH5. I've worn off some GH5 paint attempting to turn the gear.
Just a follow-up on the Olypus 60mm macro fitment issue in case this comes up for anybody else:
Nauticam sells/has sold two gear sets for the Olympus 60 mm Macro with the same part number. Either this or Nauticam revamped the part but retained the part number. The lip in front of the gear is changed just enough to effect fitment of the lens to the GH5. If you buy this manual focus gear for the GH5 make sure you request the thin-lipped version.