This didn’t happen to me, but i was grouped with the friend that ran into this issue.
During the mission “Into the Folds” done as a group, If you get the “Lost Connection” message, and relocate to a new server, “Into the Folds” thinks you are outside the instance, when you are not, and tells you to sit in the chair.
If you finish the mission for your group member(s), and this is done during the Story Mission Tier “Complete Into the Folds”, you will get a message from Mark Strakes, despite still needing to complete “Into the Folds”. Opening and closing the message, leaves the message down in the corner, and doesn’t give the mission “Callback”
We were doing “Into the Folds” together for the first time, so during the Main Story Mission. We had defeated the family, and finished the cutscene with Che. Shortly after my friend lost internet connection. It wasn’t long enough for the game to crash completely, but it was enough for the game to give the “Lost Connection” pop up, where it asks if you wanna change servers. So she changed servers, and was put back into the instance with me.
This is where it got a bit strange. The game reset “Into the Folds” as if she had left the game/ paused the mission. We went up stairs, just in case the game would realize she was already inside, but it stayed stuck at “sit down in the chair” tier for entering the instance.
We finished up the rest of the mission together, only my mission having any progress. Once we left we both got the message from Mark Strakes, but my friend still have to “Complete Into the Folds”. The message doesn’t disappear nor gives the mission “Callback” when closed on the “x”. It simply goes back in the corner.