Anyway, somebody somewhere about a decade ago seems to have injected into the heads of such rule-makers that users who paste their password confirmations defeat the purpose of the confirmation mechanism, which was leading to excess support requests for forgotten passwords. So, therefore, pasting into the confirmation box (or even better, both boxes) should be disabled.
Never mind that password rules have gotten more complex, that allowing users to temporarily preview their passwords instead is now recommended, or that the use of password managers and online password resets means even if the original concern were valid, it's now moot. The rule exists, and so it must be followed.
At some point these corporations do lurch forward (or die), so eventually this will get changed, but it'll happen way slower than it should.
Prevent that, you stupid website, I dare you!
What should the developer do exactly? Ignore the ticket? Educate the manager who’s perhaps three steps up in the hierarchy and doesn’t even know the person’s name who is charged with implementing the misfeature? Neither would go down well.
Also, the error he got when he tried to put in the password the first time is likely because there's a mismatch between what it claims the password rules are, and what they really are. He might have exceeded the maximum password size (yes, I know they're supposed to be salted in the backend, and maybe then even are, but you still run into this). Or it might be that he used disallowed punctuation (some sites seem to dislike anything other than question marks and the ones over the 1-2-3 keys... I've personally seen the percent sign and ampersand both cause problems.
If there were some little embedded xml file that my password manager could pull from the page automatically that would tell it what the rules are, then I wouldn't have to debug your shitty account creation systems, nameless developer drones out there working for big companies! Not that you care.
FTFY.
You can say no but management isn’t under any obligation to capitulate, and often won’t.
More over, it’s often solutioneering as a result to some other management identified issue that devs have pushed back on.