Check in was uneventful today to Costa Rica other than the shear mass of people traveling for spring break. The Ascent/Summit lines were longer than I had ever seen them.

When we reached the kiosk to check-in, the system prompted us to see an agent when we entered our reservation code. Seemed like other international flyers were experiencing the same thing around us, which might have had something to do with the super long lines. After showing our passports to the agent, she printed out the boarding passes and we were on our merry way. No special screening was encountered with TSA and we used the premium line like always.

So, the question remains from my OP as I don't have any idea why we couldn't check-in online.

Glad to be here with temps in the mid-90's and relatively low humidity. Spring break is off to a great start.

P.S. No pancakes on the flight today. Was looking forward to trying them.