I have encountered this issue. Progression is stuck at 99% (69/70) due to Supremacy: Progression being stuck at 36/37 even tho all the other accolades in the category are completed. I have a screenshot but not good with reddit and can't seem to post it here.
Thanks, can you DM me your gamertag/ID so that we can review your account online as a case study? Having your ID will also help us "trigger" the accolade manually if need be.