Golden gnome not appearing even though claimed

I have been collecting all the gnomes in mount steep recently. I looked up a map on google to help show me how many I had left. When I looked in the Steep Mines for the remaining ones, it turns out I already had 1/2 that it sad I had missing, but my map still shows that I don't have it even though I do. Not sure if this is a bug of some sort, but I would love some input.