Hi, recently had an AT&T update. Ever since, phone doesn't seem as responsive. For example, swiping from page to page, clicking on an app to open, etc. It seems to hesitate before engaging in the action selected. Is this coincidental to the update or could it be the battery is aging since it's probably 4 years old. The battery is holding it's charge and doesn't require charging except every other day. I don't want to spend $39 on a new battery if it's the daggone update! Please advise. Thanks.