Notice in the Carto rendering that there are two buildings with number 37. There should be a hole, but another building appears there. Looking in the editor, notice that those buildings have redder colouring (compare it to it's neighbours). The outer way (way/310598342) has the same tags as the MP (relation/19290218) which is not how they work. The outer way shouldn't have any tags, only the relation should have them.

P.S. The easiest way is to draw a line for the inner part, select the building and the newly drawn way, then press C. iD automagically handles everything.