Commlite Canon Lens adaptor putting black vignette on photo (EF-EOS R)


I have Tamron 18-270 Lens F3.5-6.3 on a new Canon RP camera. I bought the Commmlite adaptor to use my old lenses.

I am getting a black ring around my photos (I can see this in the viewfinder)

I am new so please forgive the question if it is obvious.

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