Hey ticki_52,

at least
https://www.openstreetmap.org/way/1281809899/history
is overlapping
https://www.openstreetmap.org/way/168180635/history
in southwest / bottomleft corner (two nodes are not connected to a nearby node on the other object)
When saving you would have encountered an overlap warning. Here you have chosen to add layer=1 to the building. If there is only a thin roof overlap (and assuming building from cadastre is relatively accurate), layer=1 should not be added. It is more likely the garages are slightly smaller and you are tracing over some blur or vegetation. In this case it looks like the left garage should have its left wall moved to the right, onto the building outline. The roof seems to fit on aerial imagery, but the garages don't quite. Don't forget to connect the nodes and remove the layer=1 tag from the main building.

Regards,

Daniel