I will say when I added my coris wrasse he was out in the open the first day or two then was completely missing for about 2 weeks. Then one day he just started coming out again
It’s an interesting fish. He’s first to come out in the morning and he “goes to bed” around 6-7 pm Daily, even if the lights are on full. He seems to have an internal clock, and he has a sand burrow / cave he made under a large coral I have. Once he goes to bed he won’t come back out until the next day, even for food.
And when he hid for 2 weeks, he completely hid. Would not come out for anything. I thought I unfortunately lost him.
I wish you the best. And wouldn’t be surprised if one day he is back like nothing happened.
Maybe sneak up on the tank early in the morning before lights come on, from a distance and see if you can spot him