Legendary Achievement bug!!!!!!!! plz help

me and my wife were doing legendary run through of Halo ce anniversary on the Master Chief collection. We completed the campaign and even seen the alternate ending but we did not get any legendary achievements which is very disappointing for putting in all that hard work for nothing.the only skull we had on was grunt birthday party. So plz fix this bug

Your service record only shows that you completed Pillar of Autumn. I ran into a couple of missions in Combat Evolved and Halo 2 where I had completed the mission, but for whatever reason I didn’t get credit for doing so. I’ve gotten into the habit of checking my progress after each mission. The strange part is that on the Mission Selection menu, the game showed that I actually had completed the mission on Legendary. However, here on Waypoint, under Service Record, and the in-game achievements lists, my progress would not update. Sadly, going back and re-running every mission it messed up on has been the only thing that has worked for me.

Go to your career and look at the Halo CE section and see how many it’s tracked that you’ve completed. Also if you had any levels on save and were waiting to beat them and were forced to download an update, all your progress was made void even though you picked up where you left off and finished the mission.