Hey guys! Just wanna share a workaround however it may not work for everyone.
So ran into this problem by accident. I found the solution before the problem.
After getting off the car I went near them and Panam started saying "Ok, the Miletich convoy will be traveling" etc, etc. I immediately notice the tower and went inside. The mission progress updated (which is what suppose to happen) so I opened the door to the tower. I loaded to an earlier save because I thought I needed to discuss something with them but didn't do it right. So here it is, I loaded and just stood there in the middle then to my surprise it didn't proceed. Which is why I'm here. So what I did is loaded to an earlier and recreated what happed. To my surprise, it worked.
Sorry for the long explanation. Here's what you need to do. After Panam says "Are we ready?" she will immediately continue the line "Ok, the Millitech convoy" etc etc. During this time, head into the tower from the back, head the way down to the door where you suppose to open it for them and the mission will progress normally. After Panam says "V, any questions?" the mission should update. You should be inside the room bottom room before Panam says this line as it won't work.
So basically, if you are already past the line "V, any questions?" then this won't work, or if you did not reach the room before Panam says the line it won't work.
EDIT: I tried to recreate the issue but it doesn't work all the time so I experimented a bit. I found the actual solution! I remember going to the tower immediately after getting out of the car. (Curiosity) Panam did not continue her next line as I was nowhere near her. I went back to her and it triggered her line "Are we ready" line continuing until the end. V was supposed to have a reply there which is the bug.
Hope this helps!
I'll try to record it and upload it to YouTube.