Thank you for posting your water parameters! Do you have plenty of fake/real plants in the tank? You could also try adding a floating plant to make him feel more secure, especially if he is spending a lot of time at the top of the water column.how is he stress when he is the top of the food chain in the whole tank hahahah..jk..
Any idea how to reduce that?
i have plenty of space for him to hide.
Are any of its tankmates picking on it?
Please post a video, as that will be most helpful to rule out any medical issues.