I watched a few low A minor league games where a prospect out of HS was clearly overmatched. He also clearly had a lot of talent. The next season he was still in the same league and he did a whole lot better. I think Robert went into a similar situation and has done as well as can be expected.
My guess is that the Stocks have found the transition from HS ball in a strong league to major D1 ball to be a bit tougher than expected, but Robert seems to have handled it quite well and I would expect him to continue to improve as he gets more experience under his belt.
He seems to be fairly physically mature despite his youth, and he's fairly mature for his age academically and socially so I wouldn't expect that to be a major factor. What he lacks is experience and he's getting it. I think the Stocks made a wise choice and wish Robert the best of luck in college and in next year's draft at the grand old age of 19, the same as some highly touted high school seniors.