The object you’re supposed to loot to get the engineering plans either isn’t interactible or isn’t spawning/respawning meaning the quest can’t be completed. Only the “Alpha” quest is bugged this way; the “Beta” quest to get the letters worked as expected for me.
EDIT: Still bugged in build 70338.
EDIT 2: Still bugged in build 70374.
EDIT 3: The quest target appears for me now. I had to drop and pick back up the quest but it is working for me now.