Date & Time: 3/14/18 - 3/15/18 (11am CST)
Frequency: Once
World name: Balmung
Character name: Purple Yam
Class/Level: 70 Dark Knight (6 in Eureka)
Party or solo: Both
Area and coordinates: Forbidden Land, Eureka Anemos

Steps:
1. Played quite a bit of Eureka last night increasing my level from 3 to 6.
2. Completed both the level 3 and level 5 quests and assigned the magicite (which I spelt wrong probably?) to the element board, zoned out of Eureka.
3. Changed class to Monk when I zoned into Kugane before logging out for the night.
4. Logged in today, did my roulettes (Expert, Leveling, Alliance) and beast tribe quests then decided to do a little bit of Eureka, queued and accepted.
5. Zoned into Eureka and noticed I was now level 3 and had also lost the magicites on my board, barring the first one. Additionally, the quest marker on the quest giver was completely gone, not even a red "the next quest starts at level x/return here with x" it usually had so I'm making the assumption I can't get those back so RIP me.
6. Tried switching instances and logging out and back in to see if it made any changes, which it didn't.
7. Filed an in-game bug report, logged out, then posted here as recommended by another individual having a similar issue.