Two days ago I managed to get over 5000 crystals and it seems I can't unlock the achievement. :( I was at the fragmentizer itself, the crystal shop, the crystal turn-in page and even in my currencies vault. I even checked if it got retired, but it's not. The counter of the achievement stopped at 4401 crystals. So it really seems broken to me.

That would be very nice, thank you. :3 Also good luck fixing that problem!

This should be working now if you go to the page where you turn in crystals. Can you confirm?

Yes, I can. I got it several hours ago when I was fragmenting some stuff. :) Thanks for fixing it. ❤

I wasn't the one to fix it but I am glad it is working!