Running for Transmog when the Lightforged Teleport Pad that goes back to the main area from the Antoran High Command disappeared.
This appears to be specifically because the mobs right after the teleport pad, where there are two portals were never aggroed or defeated, and then upon pulling them, it disappeared. Even after defeating them, the pad did not come back.
It was there prior to the mobs, as I personally used it, but then my friend pulled the mobs since they were behind me.
The issue is that despite dying or leaving the instance and coming back in, it starts us right at the beginning of the Antoran High Command area, and we cannot proceed to other areas. I unfortunately could not test defeating other bosses to fix this, as I went back to help them clear the mobs, despite not noticing the disappearance of the teleport pad.
I did test hitting the “Reset all instances” option, as well as completely logging out and back in, and disbanding the group.