Achievements stopped working today?

I recently have been grinding out the achievements on Halo: Reach MCC PC for the past 3 days or so. In that time there were one or two that would not unlock, such as Generous Tipper (beating the par time on Tip of the Spear) and a couple of others that I saw others posting about online. However when I continued playing today Not a single achievement will unlock or even progress. For example the “Thanks A Killion” achievement for killing 20,000 enemies or players has been stuck at the same number of kills even after playing several multiplayer games and campaign missions. Also the achievement for winning the first phase of an Invasion game would not unlock either nor would the “Fly, you fools” achievement for finding the secret banshees on the mission, “The Package”. After trying for many more achievements, it appears all of them will no longer unlock. Anyone else experience this recently or at all since launch?

Yeah I’ve been having a similar problem. I went to unlock 2 achievements. “They’ve Always Been Faster” for completing Winter Contingency without using any vehicles, as well as “Winter Urgency” for beating Winter Contingency under the par time. I wasn’t granted either after meeting the requirements for both.

They’re broken. Plenty of complaints on the Steam Forums as well. It seems there’s some disconnect between the Steam servers and the Xbox ones so stats aren’t tracking.

Weirdly enough when I launched Halo earlier today after giving it a few hours, I got the achievements. So maybe they’re just arriving a bit late?

So after logging on the next few days they do appear to be working again for the most part. There are a couple that are still bugged but I’ve heard that many people have the same issue. Unfortunate to see that one of the few games I would like to 100% has so many errors within it’s achievements.

Experiencing these same issues as well.