It's not necessarily dishonest or fudging, but consider that in all likelihood, both polls asked 2590 unique people and no one repeated. Then consider that the polls are not likely asking the same questions across the board. The margin of error is for "If this test was duplicated with a sample sizes, you will get a percent value answering in favor of x and a value in favor of y."
Quinnipiac are likely not running the same questions, nor to the same people, nor will they get the same responses because of the name of the agency. Additionally, because those aren't the only two candidates, the margin of errors don't mean same thing and you're not reporting what score Quin. gave Biden or what score CNN gave Warren. Nor do we know if all options are on the table (could Quinn have more candidates on the list, while CNN omitted low performers?).
Again, back to what was asked, the wording and options of the poll could be different (Say, Quin. asks "Who will you vote for in the Primary?" while CNN asks "Would you support [insert candidate] if nominated for President?") In the former, you're picking the candidate you will vote for, while in the later you are voting for the candidate you may not have voted for but will still support if they ran.
Also, if the question is rating support (say strong disapproval, disapproval, neutral, support, strong support) they may aggregate positive answers and negative answers as the numbers for strong and not-strong will likely not be a high percent on their own, but when their powers combine, it can get much closer to a big cut. Some will even throw neutral into the pile, just too sure up that they're still being considered, and could go that way.
Additionally, are you accounting for the fact that the margin of error will still need to balance with the other responses, so that it comes from an even 100%? In the CNN poll, if Binden has the strongest possible support in the bounds of margin of error, that means the others will have to be subtracted from to make up the difference. Suppose that Biden was really +19.6% and the difference came out of the other candidates. This puts Biden much closer to 22% while the next highest candidate might go down so that the difference between them.
Suppose both polls erred against Warren to the Margin of error. Quin short changed Warren and she goes up to +10.7%, while CNN over hyped Biden and he goes down to 10.4%. This means your 22 gap went to just a 0.3 gap. And since both polls are independent, they only have to meet 100% internally. Externally, we can fiddle with the margins to see if both are close by reducing the higher candidate while boosting the lowest candidate. We can also max them out, or short them, though that still leaves a much wider gap (although Min Quin Warren and Min CNN Biden are a lot closer than Min Quin Warren and Max Quin Biden.). If we assume the Warren error happened in both, though, we can see the results are the same. If I had Quin Biden and CNN Warren, I could probably see that an error favoring Biden brings the numbers close as well).