OK, back to square one again.

• Recover Stolen Data - Check
• Investigate Mountain Pass - Check
• Disrupt Tal Shiar - Subdue Tal Shiar Agents - All dead, but not green.
• Disable Communications Array - Check
• Free Prisoners - Check

Even rewatched the little video 2x just to be sure.

Still can't get that Subdue line-item complete. I managed ONCE with one toon, not sure how to replicate it. I have now done the mission eight times with three toons, and I'm not going to waste my time further. This sucks as I was really looking forward to checking this one off the list.

Hope this doesn't prevent me from getting the next missions

It's possible to kill the first group of Romulans before the "Subdue" objective appears, so they don't count towards it. The patch seems to have moved them back a bit, so this is less likely, but if you pull them using long-range attacks (sniper rifle, etc) and kill them before entering the area where the objective pops up, you'll still hit the bug.

I have this problem, however I managed to sort of solve it by freeing the prisoners as the absolute last thing I did.

I'm not sure if this makes a real difference but I have now been able to complete it.

The advice I was given to avoid this is to run past this first group before engaging them in combat. It's worked for me to date.

makes sense and should be an easy fix for Cryptic. Just move the mob way back or the objective trigger area closer to the map start.

Hmm. I did this mission yesterday and it worked fine for me.