Why is that?

I have noticed that Russia-Ukraine border in Crimea has admin_type=4, though on the map it is drawn as a state border. Why is that?
Really need your comment!

I think because someone changed it from 2 to 4. There seems to be an edit war on the border section: https://www.openstreetmap.org/way/238797482/history.

Map draws border line according to boundary relation admin_level tag value and ignore way admin_level tag value