I just ran into this too. I'm on a Mac in Canada. I'm uploading the page info that seems to indicate a cert validation issue. It resolved with a page reload and does not reproduce with the same site again.
Bug 1828861 Comment 4 Edit History
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I just ran into this too. I'm on a Mac in Canada using Nightly. I'm uploading the page info that seems to indicate a cert validation issue. It resolved with a page reload and does not reproduce with the same site again.