Highlights and shadows grayed out when syncing stil to video

Recently, I took some stills and a video of big white birds (Snowy Egrets) in bright sunshine.  The results were washed out because of the highlights, which I was easily able to correct for the stills in LR. I tried adjusting the highlights in PS using adjustment layers, but was not happy with the results, as I don't usually use PS for this, unless it involves masking. A friend suggested syncing settings of the still with the video in LR in Library, but when I tried to do so, the Highlights and the Shadows were grayed out, as were some other adjustments. Is this a function of the program, or am I doing something wrong? I can probably make the adjustment with the Whites and Exposure slider, but wanted to check here.

In either case, does this approach work?  Also, is it possible to see the levels of the adjustments applied to the video like you can with a still?

Thanks.