It's not buggy, it's simply not a stable sort. You don't need to "rewrite" sort, but you can easily make it stable, as evidenced by 300+ JS solutions submitted.

There is already an open issue about updating available node version, so I'm gonna close this one.

Unstable sort is not buggy, it's just unstable. And building a stable sort using an unstable sort as a base is also an interesting task in itself.

rewriting sort method for an array using any reasonable algorithm is a must

This is not really true.