No worries, them hiding is quite normal when they are stressed from the transport and bad conditions in the store and brought to some new environment after.
And yeah, there is no such species as sentangensis. Traders often make up scientific names when it comes to paros, so call them spec. sentang for now. Later when pictures are availab le may be some of our experienced members will tell you if the name is correct or not. Parosphromenus species are very often mislabeled.