Southwest Boarding Passes Not Showing on Lock Screen

My iPhone's lock screen never displays boarding passes from Southwest Airlines around departure times, even though Suggest on Lock Screen is enabled.

Thanksgiving was the first time I flew since upgrading my iPhone to iOS 10 and it still wouldn't display my boarding pass.

I mostly fly on Southwest, but my iPhone has displayed boarding passes from every other airline I've flown on in the past year.

Any ideas?