
He wants a different constellation because his old one practically did nothing for him..
He was thankful for being chosen, but in order to reap the benefits of his constellation, he had to keep rising his level and he could never reach that specific level. The regression was the last gift his constellation gave him, and besides not being able to choose who appears infront of him, why would he pick a constellation that benefitted him very little for close to 25 years over a luck constellation that's helped him gain 100 times more fortune than his last one. Besides, his old constellation probably won't appear because he is no longer considered a late bloomer.
He already has a constellation right, the one with blonde hair holding a book