Automatic Achievements Not Working for Some Students

I have the equivalent to 5 and 10 pin in my group, but they are not being awarded consistently to the students who should have them. I'm getting complaints about it being unfair!

I saw a post from last year that something similar had been fixed, but it seems to be a problem for me now.

I tried deleting one of them and recreating it, but that was a bad move since no one has that award any more!! Here's the achievement itself:

and here's a student I believe should have received it, but didn't:

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