If you look in the specification for the lock in the link you posted it says adjustable backset ..this means the latch body telescopes from 60 to 70 mm normally by moving a little lever and pulling or pushing the back side of the latch in or out..
Yep, we spotted that, but even set at 60mm, the inside end of the latch body was pushed so hard up against the timber that the faceplate was 5-10mm proud of the edge of the door!
That's weird having those measurements being out, hmmm
Yeah, I thought the same, as we've previously replaced other door knobs & they were a simple, 5 minute, out with the old & in with the new, job
The place was a Dixon Home, which means everything was done as cheaply as possible
, so they possibly found a stock of old knobs to put on
I did notice when I was pulling the old one out, that it had "2 3/8" engraved on it, which suggests it was still Imperial, even though the place was built in 1980