AD73311

Hello everyone
         I am having a problem now, as explained below.
Application:
         I used the AD73311 for industrial control and the DC output is constant.
AD73311 register configuration:
         Register B: 0x8103
         Register C: 0x82F9
         Register D: 0x8310
         Register A: 0x8001
Problem Description:
         Ability to control the rapid change of the AD73311 from 0.5v to 2.0v. However, it is particularly slow when outputting from 2.0v to 0.5V. Slowly can't be used at all.
I hope someone can answer, if you need to provide materials, I will reply in time.

Data table timing diagram:

Write registers and data flow:

Configuration register:

phenomenon:

Data loopback:

Analog loopback: