ADCLK854 lacking output

Hi, eveyone.

I'm evaluating ADCLK854 evaluation board.
I found a lacking output. I don't know it was caused by measurement issue or others.

Hear is the detail.

We input "burst clock" to this device.
It can be seem at "first burst clock" after power-up.
We didn't see it after the second burst clock.
It looks like it doesn't depend on the time from power-up.

and it doesn't depend on clock freq, I think.

I saw 2M- 200MHz.

I would like to have your advice.