Heron at Port Tobacco

Tonight we went down to Port Tobacco River to try to find the heron that hangs out there. It was back in the grasses, but came out for a moment and posed for a photo. 
I am having an absolute disconnect with the 200-500 lens. I mounted it to the D7500 to avoid the ftz converter, and the results were still garbage. I need to figure out what I am doing wrong with the settings. 
This is shot with  the kit lens that came with the D7500, mounted to the ftz converter on the z6.