This glitch seems to occur when you have recently changed your name to a name which has been used by another user prior to you changing your name who has not logged into the servers since their name change. Because of this, the system is showing you the other user's stats and if what you're claiming to be 'stats are gone', that user may not have had any stats at all.
TL;DR: You have the same username as somebody who has previously had it and they've not, according to my research, logged into the server since May so that is why you've 'lost' your stats.
If you have any further questions, you can message myself or another staff member.
QA;TL