It won’t get worse as the season goes on.
I havent heard of a case where the same player had a significantly different drop. You can send CS a ticket to clarify, but most likely you just won’t be able to redshirt anyone this year. It happens. If you didn’t promise anything, and they’re not much more talented than the guys above them, they usually take it, but not always. The only way to guarantee they’ll take it is if you inform during recruiting, but then you run the risk of losing effort credit. IMO, it’s best not to inform, unless you don’t want the player on the roster without a redshirt year.
In the future, a 6 point drop is not a big deal, unless his work ethic is already very low. Dropping from 24 to 18, for example, is very noticeable. Dropping 45 to 39 will be less noticeable over the course of his career.