Thank you for providing so much detail about the issue you are experiencing with your iPad mini. You have taken some really good troubleshooting steps already, and at this point, the next step I recommend is backing up and restoring your iPad mini.
Use the steps in this article to back up and restore your iPad mini:
If you experience the same issue after backing up and restoring your iPad mini, the next step is to restore your device to factory settings.
Find the steps in the following article:
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