Using the Webform Submission Relationship with a view based on User does not try to match submissions submitted by the user. It attempts to match "Webform submission(-s) that reference the User via Assigned element." The Assigned element is related to the webform_id value of 'template_issue', one of the demo webforms.
It used to match the User uid to the webform_submission table uid entry.
I think this problem is related to the patch for #3008750 Reverse entity reference relationship →
Active
5.0
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