If your Vietnamese coffee is co fermented with “strawberry” and actually tastes like strawberry, it’s essentially just using flavoring, not real strawberry (or, not only real strawberry).

Yes I know, it doesn't taste like strawberry, it's fermented with strawberry (or I've also seen orange, jackfruit, etc.). This is what I clearly stated, and the person above you also stated. There's no artificial flavors being added to the coffee at any decent specialty coffee shop in Vietnam, unless you specifically order some sweet flavored drink from the menu.