For me when Kenya and xenia droop its and indication I need to change out my carbon. Maybe when you moved the tank the old substrate was stirred up and effected water quality. I doubt the diff in salinity or temp was so major it did this. I can grab a xenia from my tank, through it out in my back yard in the sun for 30min then put it into another tank with diff water temp and salinity without killing it. It will just be p1ssy for a few days. Plus xenia can handle most lighting and does very well under t5. If a small piece is still left on your rock it will come back.
Good luck!
Tom
Good luck!
Tom