Anomaly Map Bosses in SSF

I played trade at the start and have seen the sealed vault anomaly map. I know it's supposed to be in a mountain biome and I've spent countless hours searching for one in SSF but haven't seen a single one. I have more citadels than I know what to do with, have seen ever single other anomaly map countless times but never the sealed vault. I need this map for the lineage supports it drops but if I can't find one soon I'm going to quit the league.

I'm about convinced that this is an bug and the map just isn't spawning within SSF. I don't know how that could be possible but that's my only assumption. Has anyone in SSF actually seen one?

Edit: I found 3 of them. I think they are coded like citadels and can't spawn close to the starting point. I was finding too many citadels so tried going the other direction from the starting point with no luck for days. Went back to my furthest point tonight and kept going until I found them