Markers properties are set to final so can not be alters. There is no setter method to change their values without trying to recreate all markers again.
I have trie the following:
markers.update(_markerId, (Marker m) {
print(m.markerId);
return Marker(markerId: MarkerId("2"), infoWindow: InfoWindow(title: "Test"));
});
The above code just hides the last marker and nothing else