How to recover a folder deleted in Notes app?
I like to go to a computer and sign in to iCloud directly. 

Much easier to see what’s deleted and diagnose if an iPad or iPhone is behind in syncing up to the cloud. If one device lags, I like to power it off while it’s in an area where WiFi works and plug into charge. 

That wakes the device and I unlock it only long enough to verify the WiFi reconnected. Let it sit an hour or overnight and most iCloud sync issues fix themselves.