[alwa]

To be fair, you can still purchase the ticket at the advertised price without selecting a specific “preferred” seat. They’ll give you a seat assignment at checkin or at the gate (usually one of those “preferred” ones).

That said, the fact that this situation is unsurprising to me is itself probably evidence of the communication problem. Google could do a clearer job of qualifying the “free seat selection” they falsely promise for that fare, and Delta could do a much better job of saying “there are only paid seats left, but if you don’t want to buy one, you’ll still get one at the airport.” I feel like JetBlue used to do a good job with that.

[steveBK123]

I think in his case it's actually a legit website bug/issue. If you try to click through without choosing a seat it doesn't actually work on this particular sales funnel and pops up an error. My suspicion its something to do with it being a very close in flight (2 hours to takeoff). So you have selected a fare with seat selection included, but there are no seats actually left .. maybe some cache isn't updating at minute level frequency.