IndexedDB error: Uncaught DataCloneError: Failed to execute 'put' on 'IDBObjectStore': An object could not be cloned

marker can't be cloned because the object stored in the map-property contains a reference to a DOMNode(#map-overview), which can't be cloned (see:Things that don't work with structured clones ).

Remove the map-property, it will not be re-usable at all because the google.maps.Map-instance will not exist when you retrieve the marker later.