Hello,
I checked this changeset.

You modified the size of a building but didn't square it.
https://www.openstreetmap.org/node/7391429944

Most buildings have right-angled corners, but it is difficult for us to draw them freehand. So please use the "Q" key to square the corners of the building. 

How to square the corners of a building (YouTube)
https://www.youtube.com/watch?v=jHuX-ILARxg

Common New Mapper Mistakes: Buildings not Squared or Circularized
https://www.youtube.com/watch?v=Xs5wX592E1o

Common New Mapper Mistakes: Connected Nodes
https://www.youtube.com/watch?v=ltn1VOiq5_0

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Happy Mapping!