Why are polygons not displayed correctly on the Yandex.map?

Question

Yandex maps

There are polygons drawn on this service:
share.mapbbcode.org/nzbiv?editid=fylfx I
export them to geoJSON and display them on a Yandex.map, but they turn out to be deformed:
https://codepen.io/UnluckySerivelha/pen/qBbvdjj

Expectation:

Reality:

At what stage does it deform them so? Maybe there are better ways to solve the problem of drawing polygons on the map?

Answer 1

Why don't you draw in Yandex ?
the service apparently has its own understanding of GeoJSON RFC 7946

Answer 2

Understand in what order Yandex takes longitude and latitude, because you have them swapped.