Incorrect value 03FF coming from remote XBEE s2. ADC input max?

I have a simple MCP9700A hooked up to a remote XBEE Series 2.
Actually 3 thermistors.
2 work fine around room temp, but one is in a “oven” type environment and although I can PHYSICALLY measure the voltage coming from the MCP as 1.53 mv, (around 225F) for some reason the XBEE is only sending a value of “3” and “255” as the MSB and LSB,… which equates to a 1000 mv and thus 158 degrees F. My oven is between 200 & 225, well within the limits of the thermistor.

OK, so the MCP is working perfectly, but why would the XBEE ignore the input voltage? Basically truncatating it/capping it?
Is there something peculiar with the ADC on the XBEE. Did I miss a configuration in XCTU? Its too tidy to be sending EXACTLY x03FF. I can watch the oven heat up and temps are right until it caps at 1000mv and never goes higher.

thx

The ADC inputs on the XBee ZB module is from 0 - 1.2V max.