features are not actually deleted from drawnItems-feature group!

[aliencraft1512]

When i actually export the feature group (drawnItems) either to .geojson or .kml , the features that i had previously deleted appear to be there even though they don't appear on the map.I reproduced the issue through this codepen [https://codepen.io/aliencraft/project/editor/AqNqqo]
Try to open the exported kml files through a third party software (google maps,geojson.io) and all the deleted features will still appear on the feature group.
Any solution to this would be greatly appreciated.
Thanks in advance.