Today I logged on to an event: "You receive 5,000 sP for having a high score this month in Matlals Jewels!"

I couldn't believe that, because I'm not actually good at it, and went to the Highscore table and indeed I am .

At the bottom of the page there is a note

"Have one of the top 10 high scores in Matlal's Jewels! Tiers: 1"

I only had that sidebar event and no achievement notification, so I looked at my achievements. This one still says 0/1 and is unfullfilled.

No big deal for me, because I am not an achievement collector (unless it gives out items, lol)

edit Friday 4th 10.20 a.m.

got the event anew, again went to the highscore list and then received the achievement event "You've earned the Matlal's Jewels High Score achievement! "

Yes, it is. Sort of. For me at least. The achievement came somewhen a day later.