ADA4807 simulation mismatch with circuit

I am using an ADA4807 as a unity gain buffer, with a +5V and -2.5V supplies. The +ve input is ac coupled to a signal that varies between 17V and 19V @ 250kHz. I have a 100k resistor to ground on the +ve input also. If I simulate this circuit using LTspice I get an output signal that varies between 0 and -2V. If I test it on real hardware the output varies between 1 and -1V. Can someone explain the difference in simulation and hardware. 

Thanks