To reduce these effects and thus make your landscape appear more realistic, tone down HDR Enhance significantly (or use the masking brush to apply or erase the effect wherever you choose). By having the slider at 36 as opposed to 100, there’s still a nice pop of details and color.
HDR Enhance scaled back to 36.
Bump up the contrast
To make your image appear less flat, bump up the contrast. Going to extremes results in lots of shadows, reducing details in any dark areas. It also saturates color in the sky and in the reflection on the water.
Contrast at 100.
By lessening contrast to about 20, shadows are still enhanced, but the details are better preserved. Note that the trees on the hill are still visible.