Current Capability Of Internal 1.2V Bandgap reference in ADuCM361

I am using ADuM361 chip for one of my sensor data acquisition project. I came across a strange issue with the internal 1.2V bandgap reference . I have followed the decoupling recommendations mentioned in the datasheet and 1.2V is generating properly on my board. The problem is i am using the same 1.2V for adding an offset to my sensor circuitry. It is basically an opamp  stage and 1.2V is added as offset just to get the readings within the ADC measurement range. An image is attached for reference. So when i am using the sensor circuitry i can see the 1.2V bandgap from the AduCM361 is overshooting ( reaching upto 2 V ). Do you have any details on the current sinking/sourcing capability of the internal bandgap reference ?? Any recommendations while connecting the 1.2V bandgap reference to other circuitry ??