If you are measuring the IC 'out of circuit' you have probably damaged it !
The absolute maximum voltage on any pin is 6V which may be less than your Fluke meter presents across its probes. It is unwise to use an continuity test on sensitive devices like this. The internal structures on microwave devices is delicate and easily (and permanently) damaged by excess or reversed voltages.
If you are measuring while the IC is on a PCB, in many cases there will be some filtering also attached to the input pin and you could be measuring through that instead.
Brian.