Check the left bar in the atlas. It says what watch stones you have and haven't got.
Socketing the watch stones raises all map tiers in that region, so just socket them according to what map tiers you want. You also reveal new maps that way.
Zana also sells maps and you can reset her inventory every time you open her mission. You don't even need to do the mission as long as you open it with a map.
EDIT: if you only have low tier maps (white maps), then don't socket too many watch stones in one region.
Map drops are rng so there's no guarantee how long it takes to progress.
This post was edited by HardyTarget on May 15 2020 08:32am