I don't use iOS but I came across New iOS bug causes some devices to crash on Dec. 2, here's how to fix it If you are affected, it should help.

Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365