Hi kmp5040, thanks for the report!
a) a 'free' player (no current subscription), and
b) your opponent was either a bot or also a 'free' player?
Then this behavior is by design, though I'd say it doesn't make much sense when playing bots.
When playing another 'free' player (or a bot), only the 26 cards of the base set are available for the kingdom. If a player can ban 5 of them, that can severely restrict the type of kingdom that is possble. Ban Village, Festival and Throne Room, and no player will ever have more than 1 Action. Ban Bandit, Bureaurocrat, Militia and Witch, and all attacks are gone, etc.
So the decision was made in base-only games not to apply the lists in the automatch queues. As I said above, it shouldn't IMO be applied to bot games, but it is.