Steam Achievements Don't Unlock But Xbox Does

Hey fellas, I’ve come up with a problem recently on MCC as I was achievement hunting. I wanted to see if any of you were having the same problem or had a fix for it. Basically every once and a while I’ll get an achievement, let’s say I just picked up the Master Chief toy for the achievement, and I get the notification on my xbox companion app or the app on windows but I won’t get it on Steam. This hasn’t happened for every achievement I’ve gotten but it’s happened about 3 times now or more and when I try to get it again nothing happens. Anyone have any ideas on what to do?