Hey, so I would like to share my observations. I play on EU Server and had this issue since start of the game I tried everything from updating the game before start to reinstall. After tons of games which I just quit and tried new servers and tons of freezes I came up with a theory. People were complaining about different game types being bugged or at least some server had medals OK and some had them broken. So I went into custom search and found out that there is a # NUMBER for each server and to my surprise when I entered a server with # 25000(example) It had medals broken, so I tried a lower number server # 24000 and Medals worked. After a week or two I had tried different servers (added them to favorites) and this week I
saw that servers with the lowest number had medals working since midnight and the later working #24000 had them broken when just a couple of hours ago they were ok and on my FAV list.
So in short my theory is:
Servers with the lowest number get refreshed the fastest thus they have the medals working properly since the start of the week, then longer into the week more and more servers seems to get updated by DICE. This would explain problems with bugged games and the same servers sometimes working and sometimes not. This is a wild theory and I would need confirmation for other regions as my copy is locked for EU.
Cheers and sorry for long post