I'm trying to complete the quest End of the Line for the institute. After I kill Desdemona the objective switches to Kill the Railroad Leadership. After I kill everyone in Railroad HQ it doesn't complete the objective and I realized that Glory the synths body is not on the floor and it gives me a quest marker in between Railroad HQ and Old North Church in the tunnel. When I arrive at the marker there is nothing there. I've been trying to get into the escape tunnel because it looks like the marker may be underneath the area but I've already defended Railroad HQ against BoS so the escape tunnel is collapsed. So, a few questions.

1. Is there a way back into the Railroad HQ escape tunnel from the exit and where is the exit located?

2. Where is Glory the synth located at before she returns to Railroad HQ?

3. Is this a bug or am I missing something?

I've tried to go back to previous saves and switch locations before and after killing the railroad leadership. I've also tried to locate the exit of the Railroad HQ escape tunnel to no avail (I forgot where the exit is). So any help is greatly appreciated.

This is on PS4 too btw.