As a Venezuelan...yes, I've seen this.
But it's dangerous for any of us to generalize - and, unfortunately, Latinos do show prejudice to Argentinians. I met an Argentinian as a neighbor here in Mexico - and she is by far one of the kindest human beings I've ever met. She is well-read - and she knows the ugly history of Argentina and why they are seen as they are. So it's a lesson to us all to pause on classifying anyone...
You wrote this and approached it well, Vanessa.