Mapboxgl breaks when I change django language in settings

Basically my code works well when language in django settings.py is set to “en-us”
But when I try to change it I get:

Uncaught Error: Invalid LngLat object: (NaN, NaN)
at new Ha (lng_lat.js:39:19)
at Function.convert (lng_lat.js:142:20)
at Rr.setLngLat (marker.js:337:31)
at dodaj_marker ((indeks):282:37)
at (indeks):296:9

I’m changing lang because I need to get months in different language, but how does it affect mapbox?
Is there any mapbox language variable I have to edit in order to get it working ?