I can't pick free champions I don't own in practice tool

This is a huge mistake because people shouldn't be forced to first time a champ in a real game. They should be allowed to test out the mechanics for themselves in the practice tool. Why have a free champion rotation if you're not going to allow players to practice it?

I used to be able to pick champions I didn't own that were in the free champion pool for practice tool. Why can't I do it now? When did it start? I'm guessing this isn't a real feature but is a bug but feel free to try to prove me wrong. Either way, I get the generic error message 'there was a problem selecting your champion' every time I try to but only for those champions I mentioned. And FTR, right now that's Jinx and Vladimir.