I see this all the time and it's driving me nuts.
Do a pano with a Voightlander 50mm APO and the resulting stitch shows lens vignette issues at the edges. Apply the supplied profile for the lens which changes the edges a little but it's still not correct. Try adjusting the slider for this but still can't match it. Try to do a manual vignette on each photos, to the eye it looks better when looking at the photos side by side *but* when stitching a pano Lightroom ignores this setting.
I cannot be the only one? The problem with lens profiles and shading is that they are going to be aperture related but that isn't a feature in Lens profiles.
Doing it manually should work, but it doesn't.
I cannot find a way to create new lens profiles - it used to be possible but does anyone know how in this cloud lightroom?