I tried entering the glyph codes in the classified section of Halo Waypoint and it tells me that I have to view all Terminals in Halo: CE Anniversary (which I have done and got the achievement for) is this a known problem or should I just keep trying?
Were you online when you got the achievement? The reason I ask is because you need to be connected to LIVE in order for them to keep track on the terminals you have discovered.
If you were connected to LIVE, I would recommend going back through and finding them all again.
Yeah I was connected to live at the time, would viewing them from the extras menu in CE do it? Cause its gonna be a pain in the -Yoink- finding them again 
I have the same problem. I was connected on Xbox Live when I found the terminals, but the codes on Halo Waypoint don’t work. I tried finding them again, but it still doesn’t work ;/.