Weird error caused by ban?

So I tried to send my friend a couple different skins this week, without knowing he got banned. I'd never tried to gift anybody banned or restricted before so I thought it might just be an unrelated error. But this is highly upsetting, why should I be unable to gift him just because he's banned? wouldn't it be more efficient, and profitable if he just got the skin after the ban was over? I had already been planning to gift limited time skins over the winter season so as I said before this causes me nothing but trouble. And although I can do nothing about it(as afar as I know) I can say without a doubt that my friend has gotten plenty of uncalled for reports and restricts. Mostly in games I myself was in and he was never the least bit toxic. So I'd appreciate input and advice.