Those suggesting that you perform a AFMA on your R5 missed reading your original post. Canon Mirrorless bodies do not have a AFMA setting for the user. There is likely a setting that adjusts autofocus accuracy, but its done by the Factory or service center.
Lenses get bumped in shipping, boxes of them get dropped off fork lifts, lots of things happen between the factory and the buyer that can decenter a lens element or damage a lens internally so that it does not work quite right. Canon has really beefed up construction for recent lenses and their packaging provides better protection. There is also a tolerance in manufacturing between lenses that are considered as being in specification but are sub par for some users.
Some dealers let you try 2 or 3 lenses on a camera in store, but I really don't know how anyone could reasonably compare sharpness or lends anomolies that way.
This is a older article showing variation among different copies of the same lens.
A funny thing happened when I opened Lensrentals and started getting 6 or 10 copies of each lens: I found out they weren't all the same. Not quite. And each of those copies behaved a bit different on different cameras. I wrote a couple of articles about this: This Lens is Soft and Other Myths [...]