Hello elliot164,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with a SanDisk on your iPad. Have you tried restarting your iPhone? This simple step resolves a multitude of issues: Restart your iPad
"How to restart an iPad without a Home button
- Press and hold either volume button and the top button until the power off slider appears.

- Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
- To turn your device back on, press and hold the top button until you see the Apple logo.
How to restart an iPad with a Home button
- Press and hold the top button until the power off slider appears.

- Drag the slider, then wait for 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
- To turn your device back on, press and hold the top button until you see the Apple logo.
"
If that doesn't resolve the issue, does your iPad need updating? Do you have a recent backup for the data in your iPad in iCloud or your computer? If not, we recommend that you create one as described here: How to back up your iPhone, iPad, and iPod touch
Then update your iPadOS as outlined here: Update your iPhone or iPad
We hope this helps.
Cheers!