How do Protestants reconcile their confession of the Athanasian Creed with sola scriptura?

It must be admitted by Protestants that only the most banal of the 44 assertions of the Creed of Athanasius appear in the pages of scripture and that its authority is Catholic tradition, justified with inferences rather than explicit assertions, and yet they claim "sola scriptura". Isn't it more accurate to say that they essentially have treated the Creed as if it were canonized and authoritative in itself? In other words, aren't they being disingenuous? Shouldn't they say, "sola scriptura plus the Creed of Athanasius"? Or rather, more broadly, "sola scriptura plus Catholic tradition"? VERY related post