MCT at HKT for Bangkok Airways is 90 minutes - so the ticket was not valid. Also, they don't interline with Hainan so no checking bags.
Strangely it does seem bookable on Expedia.
https://www.bangkokair.com/through-check-in
I would call Expedia - ask for a supervisor (this is key!), get a case number, and request a refund as they sold you an invalid ticket.