Brew as the Tholl Do marker disappears before quest items collected

When doing the quest Brew as the Tholl Do in Kholusia, when collecting the Magma Blooms at the area around X11, Y12, Z3, if you collect one of the two blooms from the grass in that area, the red marker on the map disappears even though there is one bloom left to collect. Selecting the quest in Journal, then clicking the Map option, it says it "unable to open map at this time." If you run away from the area, you have to remember where the area was and go back to find the last grass, rather than the map showing the area like it does for every other quest.

Date & Time: 4th July 2019, 20:26 GMT+1
Frequency: Once, cannot repeat quest
World name: Leviathan
Character name: Cherry Muffin
Retainer name: N/A
NPC name: Magma Grass
Monster name: N/A
Class/Level: BRD78
Party or solo: Solo
In-game time: Can't remember
Area and coordinates: Kholusia X11, Y12, Z3
Housing: N/A
Steps:
1. Accept quest
2. Travel to area to collect item
3. Collect one of the two items in the area
4. Map marker (red circle) disappears

Connection Specs
- Type of internet connection/provider: 79.9Mbps SSE