continuation of previous comment 
You duplicated several buildings which were already mapped. You did not zoom in rather far to see the mapped buildings. See the blue note on the bottom of iDeditor.
Other issues.
You clustered some buildings. Each building need to be mapped individually.
The black stripe next to a building is the shadow. Don't include that into your building
Best regards and keep mapping
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            Published using OSMCha: https://osmcha.org/changesets/133498479
            