Southwest Transaction was showing but now is not.

Hello!

I recently booked a flight through southwest using Apple Pay. I confirmed after I got the confirmation email from southwest that it was showing on my transactions. Three days later, I go onto my wallet to pay my balance, and the transaction is completely gone… not pending… gone. Other transactions from the day are there and southwest emailed me that the flight time was changed this morning so that is clearly booked. How do I go about making sure this is paid??