You may need to do a full data backup of your iPad, either to Apple iCloud or a full Mac computer or Windows PC, and then do a full reset ( erase ) and restore of your iPad, to see if this cures your iPad issues.
You will need to have access to a full computer, like a Mac or Windows PC, try either using the Finder on a Mac that has the newest macOS Catalina, or later macOS, installed OR with an older Mac with an older Mac OS, download and install the latest iTunes version ( or latest iTunes for Windows PC ), make sure the Mac or Windows PC is connected to the Internet, connect your iPad by the USB charge cable to the computer and let the iTunes application backup that iPad,
Then go into your iPad's General Settings, under Reset, and fully erase that iPad and then restore that iPad from the full computer backup.
Make sure your iPad is, at least, charged to 50% or greater to attempt this.
If NO access to a Mac or Windows computer, you will have to seek help from a good friend or family member, with a full Mac or Windows PC, to help you out
OR
Failing the above,
You will need to search online for your nearest, “local” Apple store location and call contact phone numbers and call to make an appointment to have your Apple iPad diagnosed and options presented you.
Apple Store employees will be glad to help/assist you.
Failing that,
You need to contact Apple support via the contact support link located at the upper right hand corner of every Webpage of these Apple support communities.
Use the Hardware Repair and Device Performance support categories.
OR
by installing and using the Apple Support app found in the iOS App Store.
Tap the iOS App Store link below.
https://apps.apple.com/us/app/apple-support/id1130498044
OR
Call contact Apple via the support numbers found in the link bekow.
Contact - How to Contact Us - Apple
Tap the link below.
https://www.apple.com/contact/
Best of Luck to You!