We've tried multiple keys, even in the same night. You have to constantly disconnect and reconnect to see everyone or they slowly start to drop from your frame.
The changes I mentioned that we're making to the troubleshooting report should help us identify and fix any remaining problems with the connection code. In the meantime, have your guild members run the existing troubleshooting report before
they join your next operation (if they do it after they register for the operation it will disconnect them and that will trigger the problem we've already identified) and let us know if there's anything that doesn't show up as "passed".
We're committed to quickly making this a solid, stable product for the community so we appreciate the help in getting this or other issues nailed down.