The story I read somewhere last night is that he flat out refused to do the homework of learning the plays Daboll/NYG gave him for the interview.
Writing in an April 24 pre-draft edition of “The McShay Report,” NFL insider Todd McShay explained why the Giants soured on Sanders during the pre-draft process.
“A few months ago, the idea that Shedeur Sanders could fall out of the top 10 seemed inconceivable,” McShay wrote. “But with just a few hours until the draft kicks off in Green Bay, league sources I’ve spoken to are expecting him to slide. … I’ve heard from two different sources that his visit with head coach Brian Daboll did not go particularly well.
“The friction centered on some frustration between the two regarding Sanders’ preparation of an install package. It seems the interview process as a whole — beginning in Indianapolis, as I reported a few days after the Combine — has negatively affected the leaguewide perception of Sanders during the lead-up to this year’s draft.
https://www.profootballnetwork.com/draft-expert-shedeur-sanders-meeting-giants-hc-brian-daboll/