Triggering unearned achievements - Xbox One

I've noticed an error on some of the achievement syncing lining up. For example, on my Xbox, I have not completed Guacamelee. I still have "That was hardmode?" Achievement to earn, but on the site it shows that I have triggered it:



30/30 achievements, but only 900/1000 Gamerscore.

Not sure if it's Challenges that are throwing it off, but something is not being properly translated.

Thanks!