The phone shuts down with 20% battery
Hi everybody. I got a frustrating problem with my iPhone SE2020. For some reason the phone seems to think that it cannot function with less than 20% battery. Whenever it reaches that point, it just shuts down without any warning. Sometimes it goes as low as 12% but that's as low as it gets before it automatically shuts down. When I plug it in, it gets back on right away and shows the correct percent - for instance 20% - so it's not like it's claiming that it lost all battery. It just seems like the phone thinks that it cannot work with less than 20%.
I've sent it to repair, but they sent it back, saying that they had restarted the phone and that nothing is wrong with the hardware, that it's a software problem. They wrote that the problem is fixed with the reboot, but that it might come back if I download my security copy - and they were right - it did... It actually seems to have gotten worse. But I can't use an empty phone for anything! Therefore of course I need to be able to download my security copy to get access to my pictures, apps etc. Now I have all my stuff at my phone, but I also have a phone that I cannot trust at all because it shuts down during conversations etc.
Does anybody have any idea of what to do?
iPhone SE, iOS 14
