I was going through the achievements page and found I had several wardrobe achievements that I had all the required items for, yet never got the achievements. I only got them when clicking the "show required items" button. I have only looked at the wardrobe achievements, so I don't know if this is a problem with any others. I do know it's not a problem for all achievements, though, since I have recently gotten some automatically.

This is normal for achievements that require multiple items. I can see how it would be an inconvenience, but it is normal to have to click the ‘show required items’ button to activate those kinds of achievements.