issue with AD8066

Dear Engineers,

i'm having issue with amplifier AD8066 when driving A/D converter AD9288-100,

i'm attaching schematics, and i need to remove or minimize R9 resistor, because i'm having smaller numbers of sine signal,

and also AD9288 has internal resistors on input and they are connected to Vdd with value 28k and to GND with 12kOhm,

and when i remove R9 then AD8066 will start clamping distortion probably,

please help me to identify what is badly designed,

Kind regards,