Yes, the late Senator McCain was born in Panama while his parents were stationed there in the military. Congress addressed this by affirming that he was a Natural Born Citizen because the family was there with the military. This protected all service members stationed overseas with their families.
Congress cannot enact a change the definition of natural-born Citizen other than by way of a specific amendment to the Constitution, the wording of which unambiguously requires such change (vis. this is one reason why the 14th Amendment did NOT work a change to the original meaning of the Constitutional term natural-born Citizen).
Congress whenever it chooses can of course bring about a change to its existing Naturalization statute by means of enacting an ordinary new statute. The 14th Amendment is a mere amendment to the Naturalization statute, even though it was strategically (and admittedly through very hard work) elevated to the status of Constitutional Law (i.e., laws that are very much like any other law except (in part) that they are particularly hard to change or remove or supersede once they are successfully enacted).
Resolutions, on the other hand, mean precisely nothing, and do nothing, in this area of law (an uniform Rule of Naturalization).
Firstly, he was born in the naval hospital. There are records and I have seen them. That business about him being born off base is just a lie that has been spread around.
Secondly, Congress doesn't create natural citizens. Their only power is to create naturalized citizens, and their opinions do not matter.
They can claim McCain was or they can claim he wasn't. What congress thinks has absolutely no bearing on what is the true case.
As the correct understanding of "natural born citizen" traces directly to Vattel, and as Vattel specifically says the children born in foreign lands to fathers serving as soldiers for their country are "natural born", I therefore conclude that McCain was a natural born citizen, even though he was a corrupt piece of sh*t who turned against his country in his declining years.