Did you actually find the necramite in this particular instance? I don't think this is exclusive to the new tile(set)s because I am having problems with markers and other icons on the map not appearing in other tilesets too. Things like normal crates and caches, the 2 markers for the friendship doors, kill markers, objective markers etc are all sometimes randomly not showing up on the map or the actual game itself.
Things like this are rampant now. For the record I have only ever seen this happen to me once before at very high ping when I was not host but now it seems to be about 1/3 caches are not showing icons. The only thing I can link this to is an undocumented change to the loot radar: we now have a lot more vertical loot radar since Dante than before. I don't know if it's spherical or a cylinder of height matching horitzonal radius but since this has happened something is majorly wrong with the map UI. Something I've noticed is that if you open the escape menu and return then the icons showing up on the map will change, but still won't necessarily be showing what's in range correctly. This is the first time I've seen someone with a very similar problem to what I'm having though and I hope this gets sorted,
T