Changing IPhone Region

Hi! I recently moved to Canada, and I’m trying very hard to change my phone region in order to access my digital banking app. I changed the region and can see the app now, but for some reason it now says “account not in this store.” I’ve looked it up online and tried all of the suggestions and instructions given by Apple. I’ve put in my billing address like 8 times because I fill out the entire change region screen and press done and absolutely nothing happens. Please help!!!