You can swap and use the new providers sim card ( services usually get transferred over anywhere from five minutes, up to twenty four hours at the most)... Most people will just keep using the old sim until the number has been ported. When your serv...
Have you tried going in on the app and selecting subscription and scrolling to Midway of the page and select change subscription?Instead of selecting 5G or 4G just select all ( third option from the left) although it can be located under 5G as well ...