iOS 15.1 issue

Hi FaNa83,

Welcome to Apple Support Communities.

We understand that you're experiencing a few issues with your Home screen not rotating, AirDrop not working, slow response to touch, and you can't find WhatsApp listed in your Settings to adjust notifications.

Restart your iPhone. Make sure you do not have any third party security software installed. Remove any VPNs you may have installed. Check that Portrait Lock isn't on from Control Center. Continue with additional guidance from Rotate the screen on your iPhone or iPod touch.

What happens when you are using AirDrop? Check that you are set up as mentioned in How to use AirDrop on your iPhone, iPad, or iPod touch.

You can adjust the speed that your device responds to touch. Go to Settings > Accessibility > Touch > Touch Accommodations, then turn on Touch Accommodations. Continue with Adjust how iPhone responds to your touch.

For the issue with WhatsApp not showing in your Notification settings, make sure the app is running the latest version from the App Store, force close the app, and if it continues, remove and reinstall the app. This may result in data loss, backup your iPhone or you can check with backing up only the app data. We provided some helpful links with additional steps to work through.

If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open

How to back up your iPhone, iPad, and iPod touch

Regards.