Notes disappearing, App Hanging

While using the Notes application on the iPad, a large chunk of my notes (written with the Apple Pencil and duly saved) disappeared. They were neither on the iCloud nor in the iPad. This issue keeps recurring almost everyday. Even after I stopped the sync to iCloud, similar issues arose. What can be done?

The iPad is fairly new so it’s pretty disappointing that such challenges are arising.

Along with this, the split screen function is also hanging, as well as the Freeform app.

The markings I make in the pdf - saved to Books - are facing the same issue.