I bought a Yashia Goby on Friday and since that day he's hiding

I know where he hides so I can target feed him, he's eating but he won't come out

Do you guys have any experience with Yashia Gobies? How long is he going to hide
90G tank
Livestock:
1 Yellow Tang
1 False perc
1 Black clown
1 Cherub Angel
They're not aggressive, they don't bother any new fish and they didn't attack my goby.
Thanks in advance
