I was working on my fourth character in The Division and I admit I rushed it a bit and when I completed the mission and killed the big guy cleaner with the super flamethrower and lots of armor and health, I opened the map and fast travel back to the BoO instead of taking the elevator and waiting for the cutscene at the end. When I got back I went upstairs and tried to find Paul Rhodes but he was nowhere to be found. I fast traveled back to the Subway Morgue mission and walked all the way through and saw Rhodes up in the control booth and was thrilled until I got into the elevator. It didn’t work.
I went back to the BoO and went to where Rhodes should be at his desk and there was no prompt to talk to him. I held down the button anyway to try and talk to him but it didn’t work. I tried going back to the mission to restart it, and although I was prompted to start it, when I moved forward there were no bad guys. Looking at my map the icon for the Subway Morgue mission was white, and its supposed to be yellow to complete the mission. I wasn’t even going to try that mission on Hard, especially not solo. Next, I logged my player out and went back into the game and back to the Tech Wing again, but no Paul Rhodes.
What did work was after I had logged out, and gone back in again and found Rhodes still wasn’t there, the Subway Mission icon on the map was again yellow. I ran through the entire mission again on Normal and at the end I made sure to get into the elevator. I was rewarded with a cutscene and official complete of the mission, and was able to then fast travel back to the BoO and unlock the Tech Wing after talking to Paul Rhodes.
Unless something is very wrong and you also fast traveled before the elevator I do not believe you should have to play through again on Hard, or start a new character – which were suggestion I read online tonight.