So there was an update recently which did not fix this bug, so what happened was I was doing the echoing void dlc and I was in the end I saved my character to the cloud on pc and I had gotten all 6 eyes of ender on pc. When I had downloaded my character from the cloud to Xbox all of my eyes of ender said 0/6 and the end missions were locked. Now that was not too big of a problem I thought I could just kill the special endermen and get the eyes of ender again when I killed them they did not drop the eyes of ender which effectively locked me out of the dlc. So the eyes of ender will not appear anymore they are just gone 

Edit; I forgot to mention I have tried uninstalling and on Xbox and have also tried uninstalling the dlc 

Most recent edit: So I think I resolved the issue myself I just went back onto my pc and reuploaded my character through the cloud it must have been something up with the cloud saving because now I can play the dlc on my Xbox. If u want something done do it yourself I guess