iPad storage full notification error.

Thanks for providing the screenshot. It adds a lot of clarity.

When that pops up, I suggest clicking “Manage Storage” to see if that paints a different iPad Storage picture than you showed above.

I believe the Goodnotes app requires a lot of scratch space storage while it is running.

Yes, that app is very likely the cause of your issues.

Adding to helma145’s suggestion:

About storage on your device and in iCloud - Apple Support

“Full” does not mean you have occupied each and every byte of storage. That much is not available to you.

You need an absolute minimum of 10% of your iPad’s storage free at all times.

Cheque if your iCloud storage is full.

Of course, you have not told us the context in which you see a storage full message. Perhaps it refers to your computer.

Glad your issue is resolved.

Enjoy your Apple gear!