i agree that some DPs maybe user error, but i personally know someone who has done this before and the last time it didnt work. same thing also happened to my colleague for C1 portal and DL. when i checked reddit, there are also inconsistent DPs for DL. some said that they managed to do it after making a change on the DL app, but others reported that the change and/or cancel button is just greyed out on the app. in both of these cases, it is not their first rodeo. and when there are that many DPs, i just think it is better err on the side of caution instead of dismissing all of them

eta: and DPs are just DPs. sometimes they are just inconsistent because the situation is. for example, recently there is the citi 4506c issue. many people are complaining that citi doesnt inform them when their forms are filled in wrongly or when IRS rejected their forms. they only know after they called in to enquire. well, for my wife and her friend, citi called them to inform them that the IRS rejected their forms without them asking. and i think it was quite soon after they receive a response from IRS because IRS also sent us a letter informing us of the rejection and that came slightly more than 1 week after the phone call. may not be the best example, but it is just the most recent one where what i experienced is completely different from what everyone else did