oh wow, that remind of something that happened to us too, maybe that could also be the same problem
in 2021 or 2022 I believe, my wifes parents sent her a package with medicaments from overseas, like they did for years, but this time, it was confiscated in Miami.
We never received any letter, but her parents overseas received one letter saying that the package was confiscated!
maybe that could also be our case, because they did not mention "immigration" on the reasons for denial...
but on the other way, I never tought that package was a big deal, I just remenber that now after reading your comment