Microwave does not heat food placed in the center...

Question

Food placed in microwave will only cook/heat around the edges. The center of the plate will be left cool or cold.Example: Anything (say bacon)you put into the microwave to cook must not be placed within about a 3 inch diameter circle in the center of the rotating plate. All other area of the food will cook but it seems that the microwaves are not being spread over the center of the food being cooked. Thank you.