I am also having this problem. I have done all of the escorts several times and still have only got 2/3 on Vigil Field Supporter. I am pretty sure that the two events I did get credit for were the escort to the west wurm and to the east wurm, and so the middle escort seems bugged for me. The middle escort was the very first I did though.
This does not seem to be common though, I have asked around in map chat and noone else seem to have this problem. They all just go like NO it is not bugged, you are lying, you did not do all the escorts and so on.
I guess it could be the case that there is some extra requirment I am missing, if so I would be really happy if someone could explain what i need to do….