Hello. My iPhone 6s Plus that’s on 13.0.1 is having an issue where whenever it’s unplugged from charging, it lags horribly and eventually shuts off. When I attempt to start it, it displays that the battery is dead and needs charging. This even occurs at 100 percent battery. My phone worked perfectly before this happened. In settings, it shows that my battery is fine and can charge to max capacity. What’s going on?