It sounds very normal what your starfish is doing. Even though I know some will give me hell for it I do own one as well and at night he climbs the glass and does all sorts of weird things but come day time hes back buried in the sand eating
pods im sure. That is what your starfish is probably doing he is looking on your
LR for food due to the fact hes a scavenger. Many say if your tank is too small the star will deplete the population of
pods quite quickly and starve himself to death so if thats the case and your tank is small you might want to try target feeding him.
HTH