I find that I am unable to log in to the forum while connected to the Four Points Sheraton WiFi. Same issue with both my iPad and my Mac Air. Cleared cookies and cache and did not help. Get the thank you for logging in page, but clicking Enter the Forums sends me to the Guest Access not allowed page.
Switch to DTAC SIM connection and log in works fine.
If you're being thrown around during the login process, that's indicative of the establishment using True internet which caches the cookies. There are no problems with other ISPs.