How did you perform the transfer from the old to new iPad? While you created a backup (always advisable to have at all times), did you at least attempt using QuickStart - which may help with moving App-data that is not necessarily included within a backup?
These support pages should get you started with setup of your new iPad - and the methods of transferring your data from old to new iPad:
Set up your iPhone, iPad or iPod touch – Apple Support
Transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support
Use Quick Start to transfer data to a new iPhone, iPad or iPod touch – Apple Support
If the donor iPad, from which you are transferring your data precedes iOS12.4, QuickStart will not be available. Any device running iOS12 is capable of update to iOS 12.5.7.
“Transfer” is rather a misnomer. In reality, your data and setup is merely cloned to the new device. Nothing is moved or removed from the original device.
An alternative is to restore either an iCloud or iTunes backup to the new device:
How to back up your iPhone, iPad and iPod touch – Apple Support
Restore your iPhone, iPad, or iPod touch from a backup - Apple Support
As you still have the original iPad with intact data, you can reset your new iPad and repeat the transfer process - using QuickStart:
Settings > General > Transfer or Reset iPad > Erase All Content & Settings
If QuickStart doesn’t resolve transfer of your App data, check to see if the App itself offers an online backup option. If necessary, consider contacting the App Developer for assistance:
How to contact an app developer - Apple Support