Gadgets disappear on side screen temporarily

A forced restart may be helpful - as this will often resolved an isolated issue:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

You are showing a notification on the settings app. If you haven’t updated to iOS 14.0.1, I would suggest that you do so. After that, I would try the forced restart again and see if that helps.

I was having the same issue with disappearing widgets and after deleting and reinstalling the widgets and a forced restart, the widgets worked as expected.

You might be best advised to seek assistance directly from Apple Support. You’ll find the Contact Support link at top-right of this page.

Alternatively, you can open a support case from the excellent Apple Support App. If not already installed on your iPad, it can be downloaded from the Apple App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044