Advantest R3172 tracking generator 16MHz offset frequency

[Samogon]

Hi,
When i try to use TG on the unit it is sweeping +16MHz of center frequency set.
I found it when tried to setup some test. And found that it will not track at all.
I connected oscilloscope and see that it outputs proper amplitude signal but 16MHz about setting.
Also connected counter and it shows same shift i guess it is exact 16MHz measured with zero span set.
This SA had dead battery so i have setup new and calibrated, unit passed self calibration no problem.

Can someone give advise where to start please?

Thank you.