picture in picture mode

Currently, the Apple TV app has this feature for sure.

If your video player app (YouTube) doesn’t support PIP right now, then you may have to wait for the developer to update the app compatible with iOS 14 with PiP.

Alternatively, you may go to youtube.com in Safari, play a video, and make it full screen. Now you can select the newly-added PIP button on an iPhone running iOS 14, and the video will pop out from the page. You can change tabs or navigate to different apps, and the video will keep running in the PIP.

See the pic below, a snapshot was taken on iPhone SE 1st Gen iOS 14.0.1

YouTube is not an Apple Product. Contact the app developer here --> App Support or YouTube Help - Google Support

WhatsApp is not an Apple product. Contact the app developer here --> App Support or WhatsApp FAQ  Or Restoring your chat history - WhatsApp FAQ or Contact WhatsApp

WhatsApp Business is not an Apple product. Contact the app developer here --> Developer Website  or App Support  or WhatsApp business products - WhatsApp FAQ

Hi. Did this get resolved? I’m facing same issue as all other apps work perfectly but the pic in picture doesn’t work on my WhatsApp

Maybe with a new upgrade to WhatsApp, it might work.