Hi!

THere is indeed a transition from 3 to 4 lanes here. Please follow wiki on placement transition and do not remove these tags.

When we use placement=transition with width:lanes:start or width:lanes:start, we must include the partial lane also. Thus the tags were correct before the edit. See the updated version of the wiki on lanes (motorway section): https://wiki.openstreetmap.org/wiki/Lanes