Foxface hits often

Hello, I have had a small foxface in my 55 dor a while now and I find he hides in a cave a lot and is startled easily like the sound of pump turning on in the tank next to his. Any suggestions? Water is good 1.023 sg, 8.1 ph, 77 degrees, no nitrite or nitrate phosphate less than .01. Other tank mates are: blood orange clownfish, anthias, watchman goby, and neon green wrasse