I updated my iPad Air and now can’t see my favorites in Safari—either when opening a new page or using the side bar. Why?

Have you already tried to force restart your iPad?:

• On an iPad with a Home button: Press and hold the top (power) button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top (power) button. Only when the Apple logo appears (it might take 20-40 seconds), release that button (ignore all other screens that might appear).

If the issue still persists, contact Apple Support using this link:--> Get Support

Regards

Giulio

Here's how they work using iPadOS14:--> Bookmark favorite webpages in Safari on iPad - Apple Support

Reagrds

Giulio