As I cannot reach the chat, nor can I phone it, nor is there a way to post an email, I have only one possibility and that is to post this error to the forum.
Lightroom CC arbitrarily changes the sort order. Sometimes after generating a panorama or editing outside of Lightroom, e.g. in Photoshop the app changes the sort order from "creation time" to "user defined" (I don't know the English items for this sort options.)
This behaviour of the app has been annoying since Lightroom 4 and I am baffled that this is still not working. This does hinder the professionals in their workflow and it cannot be that hard to fix.
Are you using Mac or Windows?
Which version of LR are you using ?
Lightroom 2015.1.1 CC
Camera Raw 9.1.1
Mac OS X 10.10.5