AD420 Unstable output voltage signal

Hello! I have a problem with ad420 voltage output. I need VOUT=0-10V. 

In my scheme i have 4 independent AD420.
From 0 to 3 volts on the AD420 (6 volts after the amplifier) everything works stably. Increasing the voltage, the output signal starts to somehow jitter (as shown on the oscillogram). I use VLL for power ADUM1401.

Why is this happening?

PS In the current version of this scheme, everything works stably and without problems.

P.S.1 I have a video - DAC AD420 problem - YouTube