My iPhone seems to behave differently after nearly every automatic update. I end up having to relearn basic functions, which is really frustrating. For example, the button I normally use to start the timer sometimes disappears. Photos and videos also aren't saving properly. What could be causing this, and what troubleshooting steps should I try?
2 Answers
Before doing anything drastic, make a current backup and install any follow-up iOS update available. If the problems continue, you can try resetting all settings; this won’t erase your photos or apps, but it will reset things like Wi-Fi networks and preferences. A factory reset should be the last resort, followed by restoring from a verified backup.
It’s hard to diagnose without the iPhone model, iOS version, and exact behavior. Check whether the phone is low on storage, since that can prevent photos and videos from saving. Also confirm that the Camera and Photos apps have the necessary permissions. If the timer control is missing, fully close and reopen the Clock app, then restart the phone.

A screenshot of the missing timer button would help determine whether it’s a layout change or an actual app problem.