As seen in the attached video, an Overworld map that's hung on an item frame in the Nether, will still display a green arrow. In the video, i break the map in the item frame, while holding the same map in my offhand. You can see that the green arrow immediately disappears, thus providing proof that that particular map was generating the green arrow.
I have noticed the same bug with an End map hung in the Overworld.
Thank you for your report!
We're actually already tracking this issue in MC-135530, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
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