Biggest thing that surprises me is that you noticed and it appears to be a new experience for you. For as long as I can remember people in shops speak different languages in front of the customers. Mostly Indians/Pakistanis, but I canny say I would even look at it as anything unusual.
Racist, nah, just sound like you got exposed to something you aren’t used to.
Form me racism needs to contain a nasty element to it. You clearly don’t have that, just went out your comfort zone.
What you do with that experience going forward will decide if you are racist/xenophobic or not.
Personally, i’m a live and let live type, no problem with people speaking their native language.