Progress reset

Yesterday I logged in again after a long period of absence (don't recall how long - a year maybe). To my surprise my online progress seem to have reset. I think I was level 50+, but it was now 0. Is this some known issue or what can I do about it ? ( Did a few searched about it but did not find anything )

In the past, all the ranking levels were been reset after the patch 2.40 if I'm not mistaken. After the patch 2.51, the ranking levels were restored and added up with the progress done between those patches.
You may get back your online progress if you log in again.