Appears that Air Asia not flying to Chiang Mai, Thailand, but exact dates of 'flight unavailable' are not given.
Why don't they simply make an announcement that between such dates flights cancelled? But no, keep the news hidden.
Probably also other flights thruout Asia also 'unavailable' but you will need to process the online booking to learn this.
Korea Air won't refund tickets to people too scared to fly to Korea- but WILL refund tickets to China, HK...(probably because HK isn't going to let them come...).