Today my team mates and I found what appeared to be a bad bug on the last City mission. I'm referring to the "hard" one in which you upload a virus and rescue the Deferi from Borg alcoves. I know this worked during the last Defera Invasion event because I was able to finish it and turn it in.
Today, after uploading the virus, the mission objective would change to helping the Deferi and a few Deferi would appear in the alcoves... and then nothing would happen. No Borg would spawn and there was no pop up button for helping any Deferi or for the Borg node. We tried this on all available Borg node areas and were met with the same results. And yes, we moved over every single Deferi and explored every single inch of the area looking for any action that could be taken.
I know we were not the only group having this problem. Many other teams were bouncing from node to node trying to solve this mission as well. We left, finished the temple missions, and came back and it was still broken. We were able to finish all the other missions, including a sphere "hard" mission that involved killing a giant Borg boss.
We spent a lot of our valuable and limited event time trying to finish off that last city quest.
I'm going through with a team of 5 right now and we are having this exact problem. We are bouncing from node to node. We activate the terminal, newly assimilated Deferi beam in and that's that. Nothing else happens.
The mission isn't broken. First time throug it today, and we though it was bugged or something too. Just wait for a few minutes and the second wave will walk out of the cubicle things. Patience is all that is needed. Use the time to prep.
There is a solution to broken boss rooms on Defera. First try one of the other boss rooms. This can work on PP or City. But it sometimes doesn't work on city. In that case have your team all beam out or switch instances. This has worked every time for me. It does eat up your time... but at least there is a work around solution.