I am not sure if this is beta related or not since retro achievements have been hooked back up. One thing I have noticed is that some (not all) of my games are showing that they do not have a retro achievement available on the side details bar in LaunchBox even though they do according to the retro achievement website. I have compared the hash of my games to the hash on the retro achievement website and it matches perfectly. One example of a game is Bangai-O for the Sega Dreamcast so I looked in my Dreamcast .xml file and noticed that the retro achievements hash did not match the hash that was on the retro achievements website so that's probably why no achievements showed up for that particular game. I am assuming that the hash that is in the xml file is what is pulled from their website, so not sure why that hash did not match the one from their website? I have also ran a complete rescan of all my games for retro achievements in LB and it is still pulling back some wrong hashes from certain games when I compare them to the hash on the retro achievement website as they do not match up.
One other thing to note is when I just run the game through Retroarch and not LB it detects that I have the correct hash and shows the achievements that are available.