Ruby

Do not erase the phone over this, and be careful with the advice to Reset All Settings, which is the next thing someone will suggest.

Reset All Settings is sold as harmless because it keeps your data, and it does. What it also does is drop wifi passwords, VPN and mail account configuration, keyboard learning, per-app permissions, and every accessibility and display preference you have set over the years. People agree to it thinking it is a soft reboot and spend the following fortnight re-approving notification prompts.

For a problem where opening an app demonstrably fixes that app, the cost is absurd. Keep it in reserve for something that is actually stuck.

On the last item, because people reach for it too readily: erase and set up as new, then restore only data, is not a thing the standard restore flow does. You get a full restore, which brings the same state back, or you get a genuinely new device where you sign in and re-download apps by hand and lose per-app settings.

That second one does fix index problems. It also costs an evening and every app login you have. Worth it for a device that is unusable. Absurd for missing shortcuts.