It's a common problem. I had that issue too, home address was up to date, but mailing address was from PR days. Not a big deal, you can easily submit a request on ECAS (not webform) to change it. Note, if your home and mailing addresses are the same, the mailing address will dissapear from ECAS after the update takes effect.Thanks meayman. I did updated the info using web form. AFAIK, I don't think I mentioned any other address than my Canadian address in my citizenship application. so just curious to know if this is something common or am I the only one with this issue.
Alternatively, I believe it will automatically change to the correct mailing address once your applicaiton starts processing, even if you don't request them to change it now. But better to do it. Took 48 hours in my case for it to update.