Hello, Sikal.

Your edit broke _every_ railway relation going through this tunnel.
I see about 85 broken relations in the OSM Inspector view today.

Please exercice caution with your railway edits. People rely on correct OSM data and you should not edit the map if you don’t know what you are doing.

In case you download railways through an overpass query in JOSM, make sure to always download the relations *before* splitting ways.

Splitting a way without getting JOSM to update the relations using it always corrupts data.