LSF0108: REF_A input is acting as a current source

Part Number:LSF0108

Situation:

REF_A= 3.3V;

REF_B = 5V Via 1K resistor to limit current during testing,

EN= +5V via 200K,

Pin 1 = GND,

A pins=open,

B pins +5V via 10k

I am finding that the Ref-A input is acting as a current source when VRef_A - VRef_B > 1.2V.  I have replaced the chip, checked the pinout and lifted the Ref_A pin2 to confirm that it is the current source. I would have expected only leakage currents on the ref pins.

Any suggestions?

-CS