Sine Encoder Problem DH061M-13-1320

Hello!

Motor DH061M-13-1320 (link), trying to rule it with Servostar S346. In a documentation of motor it is said just Feedback: Sine Encoder. 

When configuring S346, I picked 4 Sine Enc EnDat as a in DriveGUI utilite. It worked fine for a rather long time.

But recently something happened and now S346 shows error F04.

If I change feedback type to 1 Sine Enc Enc 5V it works fine, but now I lose start position with every power-on. So, encoder is not absolute anymore .

Questions are: How comes that motor responded via EnDat if this interface is never mentioned in any motor documentation? When it stopped working EnDat, was it a some hardware failure on a motor side? If no can it be fixed in any way? IDK, some hard reset of a motor or some diagnostic connection

Thanks