Destroying a banner in a non-overworld dimension will not remove any associated map markers

In the Nether, if you set up a named flag on an anvil and then right-click on it on the map, a marker will appear on the map. Normally, the marker on the map would disappear if you destroyed the flag, but in the Nether the marker does not disappear.
The marker should disappear as it should, so I would like this to be fixed.