I had to do a DFU restore on my iPhone to get it to fix. (Warning, this does reset your phone, make an iCloud backup. And ensure that you know your iCloud credentials. Your eSIM data is safe though)
Use a computer and go on ipsw.me and find your phone model. Download the iOS 26.5 ipsw (or whatever version is the newest).
Once the file is downloaded, plug your iPhone into your computer. If you’re on a windows computer, make sure to download the Apple Devices App. Look up how to enter dfu mode.
You should get a pop up from Finder if you’re on a Mac, or a pop up in Apple Devices if you’re on Windows. There should also be a Restore button. If on Mac, hold down the Option key while you press the Restore button, on Windows, hold down the Shift key while pressing the Restore button. It will allow you to select the file you downloaded.
The iPhone will then be fully reset. Once it’s done, you need to sign into the same Apple ID that you had before. You can then restore from your iCloud backup and everything should work again.