I'm having the same problem not sure why and I haven't been the host leader either. It seems like its only showing the champions I own who happen to be free this week as well.
I have had this occur also. I noticed for me that it had occurred in the following scenario:
Played a ranked game (didn't show as expected)
Played a normal dominion game, free to play didn't show
Played a normal game, blind pick, free to play didn't show
I found by restarting my LoL Client that made the Free to play champs show up again (as expected).
Could the issue somehow be relating to the fact that a list of champions is somehow being carried over, and the free to play werent in that list due to the ranked game?
I don't get it to happen consistently, but have run across this issue twice in the last few weeks.
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