iPad 6th generation

It is possible one or more of the apps you use and/or are leaving open maybe having an affect on your iPad's available storage.

A 32 GBs iOS device after drive formatting and installation of iOS leaves anywhere between 23-24 GBs.

iOS needs to constantly maintain between 2 and 3 GBs for normal iOS operation and functionalities.

This leaves your iPad with only a practical, usable internal data storage space of between 20-21 GBs.

OF WHICH you have already used nearly 13 GBs.

So that only leaves your iPad with 7-8 GBs of usable storage space.

So, it is possible that amount of internal data storage space left inside of your iPad is causing issues when leaving apps open as the apps maybe taking up temporary space in your iPad when sitting in the background app switcher.

Also, maybe eating up CPU and temp space IF these apps are working in the background constantly getting/retrieving data from the Internet.

When possible, you should go into the Settings app under General app toggle OFF Background App Refresh for ANY or ALL apps that you feel really do not need to be constantly updating data in the background when you are NOT actually using these apps.

This maybe part of your issue.

Best of Luck to You!

How much memory do you have available on the iPad? Go to Settings > General > iPad Storage

If you are running out of memory, this can cause apps to close.

OK, 12 GB free out of how many total?

Force Restart your iPad and see if that solves this:

• Pad models with Face ID: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then press and hold the Power button until the device restarts.
• iPad with Home button, iPhone 6s or earlier, and iPod touch (6th generation) or earlier: Press and hold both the Home and the Top (or Side) buttons until you see the Apple logo.

What is the actual storage size of your iPad model?

12 GBs of internal free storage space out of what total amount of internal storage space inside of that iPad?