I have been to the Archipelago, South Coast, and Mountain Region before. So far all compounds with “marked” weapons, missions, or collectables have map markers with tool tips. In the Farmlands for me several compounds don’t have map markers even though they have stuff to collect (e.g. the farm to the east of Viggohem).
I have used the forum search but did not find this reported so far. If it was, please notify me and I delete this post.