Major vignetting problem

I know there are plenty of forums about this. But I just can’t solve this problem. Im using a Sony a6300 with a 7artisans 60mm f2.8 Macro lens. I have the JJC film digitizer setup (Nikon ES-2 copy) from amazon. There’s no lens correction in LR for this lens. I’ve tried Flat Field Correction with no luck. Almost makes the image worse. I’ve slowly upgraded this set and these are better results than what I would get previously with an OM Zuiko 50mm stacked with a Macro Teleconverter adapted to the Sony. I originally just had the light source with the film holder. Now I have the complete JJC digitizer set that is basically a tube that goes straight to the film with the film holder pressed up against the base letting no ambient light in. Ive tried different distances and I guess I was getting somewhat better results with a further distance. But the vignetting is still very noticeable and you’re just reducing resolution having to crop heavy. The only other thing I can think of is that the inside of the JJC tubes are reflecting light inside. But those appear to be fairly matte given that the tubes are metal. Any information would be greatly appreciated because this has been a major headache.

I’ve uploaded images of the result that I’m getting pretty consistently, the full scanning set up and the inside of those JJC tubes

It would be good to test your setup with a light source that you know to be even, with everything else (magnification, aperture) staying the same but without the tubes. Maybe a tablet or even a phone, these won’t be as bright so the shutter speed will be (much) longer but that won’t matter. Then repeat with the tubes in place. That really is bad vignetting so I’m surprised that the problem hasn’t been reported more widely if it’s the lens, or if it’s the JJC digitizer in fact.

If there is no profile you can do a radial adjustment but I’m wondering why Flat Field Correction isn’t helping.