So I kill the tunnel guards. There are supposed to be 5 but as soon as I start shooting, 1 guard disappears and the location icon shows underneath one of the shelving racks. When I kill all available guards, it doesn't complete as still showing 1 guard under shelf. Tried reloading and restarting stage but same thing every time. How can I get past this please?

I'm not sure what I'm supposed to do now? I sent an email reporting the problem to Beth and had no reply. No reply here either? Is someone from Beth even reading posts and mails? Should I just assume it's being looked at?

Bit disappointed with lack of response tbh.....

Sounds like he is either glitched through the world or is on a lower floor their might be a way to fix when they add mods.

Keep replying to the thread that is sent to your email. At first you'll get a few auto-responses that don't help, but if you are persistent and actual employee will email you. I had a progress halting glitch with the same quest (seems they didn't put a lot of effort into the Railroad quest-line) and emailed them and they let me know they are aware of how glitched this quest is and the development team is working on a solution.

I know Bethesda makes glitchy games, but these MAIN-QUEST glitches that halt progress are unacceptable imo. They had plenty of time to polish things like the main freaking quest.