issue re-obtaining moonshade earring from mission "Lest We Forget"

[Niyariko]

I have followed the guide i found on various sites online, dropped my previous moonshade earring, re-did the mission battle "Lest We Forget" and won. Went back to Grauberg[s] F-5 with the moonshade earring key item, checking several "???" in the area. No luck, I'm getting messages like "There is nothing out of the ordinary here. or "The air before you appears warped and distorted..."

I've also tried zone in and out, relog my character, waited a game day, and still no luck.

Searched thru the internet, couldn't find anything.

anyone have any idea on what I've done wrong? Please help

figured out, found out that even i re did the fight, i'll still need to do the mission "Where It All Began"