Just to check: have you tried going directly to the Thai Airways web site rather than via a link on a price comparison site? I cut and pasted your URL from the above sentence and it opened immediately in Safari but I am in Bangkok so you'd hope this web site responds quickly on its home turf. To troubleshoot why it's not opening for you, I'd try pasting your URL into another browser or in your existing browser in a Private or Incognito window to ensure there aren't any strange cookies or referral codes fouling it up for you.