Problems reordering folder contents in iBooks

Greetings MarcBath,

I understand that you are not able to rearrange books (PDFs) in iBooks as you would expect. According to the following article, you can rearrange your iBooks content by touching and holding a cover, then dragging it to a new location.

Organize books - iPhone

Best!

Thanks for responding and letting us know that that you are not experiencing expected behavior on your iPad. To continue troubleshooting, I suggest isolating the software by reinstalling iOS.

This process should not erase any of your data, but it is always a best practice to make sure you have a current backup before proceeding.

How to back up your devices using iCloud or iTunes - Apple Support

Once your iPad has been backed up, follow the instructions in the article below to reinstall iOS on your iPad and then test the situation.

1. Connect your device to a computer and open iTunes. If you don't have a computer, you can borrow one, or go to an Apple Retail Store or Apple Authorized Service Provider for help.
2. While your device is connected, force it to restart. Press and hold the Sleep/Wake and Home buttons at the same time. Don't release when you see the Apple logo. Keep holding until you see the Recovery mode screen.
   
3. When you get the option to restore or update, choose Update. iTunes will try to reinstall iOS without erasing your data.
   

iTunes will download the software for your device. If it takes more than 15 minutes, your device will exit recovery mode and you'll need to repeat steps 2 and 3 again.

If your iPhone, iPad, or iPod touch won't turn on - Apple Support

Cheers!