Elder influence blue ring not spawning

In order to get next memory fragment, you need to get Elder influence to certain tier of maps. For third memory fragment it would be map tier 8, for fourth — map tier 9. You should run maps of similar tiers or spread your elder influence to higher tier maps. Sometimes it takes only a few maps to make elder influence, sometimes more. You can also ignore this quest for now if you're in low tier maps and continue to explore your Atlas. Blue circle will appear on Elder-influenced maps, not Shaper-influenced.