I used the blue power up icon for my warlock so I wouldn’t have to do the Red War and other DLC campaigns, one I did that it gave me all the subclasses but I didn’t get my achievement. I tried upgrading everything and I also played as each subclass and it wouldn’t give it to me. I sent you the video to my tweeter to show the proof, thank you 🙏
Try going to settings, switch profile, select yours again. Usually makes them pop.