This may indeed be database corruption. Historically, the advice would be to do a soft reset, then a restore from a backup. If a soft reset isn't working, you may be running an old version of the Diagnostic Tool. It should eventually update itself, but you can speed the process up (or check your current version) by following these steps: New Diagnostic Tool Version 1.0.97. As of 2.3.3, you also should just be able to restore a backup, as that action alone now performs a soft reset before restoring the backup.
It sounds like you've already tried some of this, but I suppose it can't hurt to try again and see if it happens after both platform and Diagnostic Tool updates.
If none of this helps, perhaps an engineer would be interested in looking at additional information from your hub, but I'd start here first.
