Sorry for my bad english. It is not this item frame bug. It is about green markers on maps whether in hand or in frames. These markers should show the position of copies of the map. But as a bug they show something like a position of the map hanging in item frames in the nether. Which is a bug because the map shows the surface, not positions in the nether.
Steps to reproduce
Create a map
Open a portal to the nether.
Clone that map
Put one of those maps into a frame in the nether
Go back from the nether.
Look at Your map and notice that there's a green map marker visible on it even though there should not.