1. Video websites or players may have rules restricting full screen, which may be due to copyright protection, user experience or other reasons.
2. There may be compatibility problems or errors in the application or browser of Thai TV, which makes it impossible to watch it in full screen.
If you encounter the problem that you can't watch it in full screen, you can try the following solutions:
1. Check whether the application or browser of Thai TV has been updated to the latest version.
2. Try watching it on other browsers or devices to determine whether it is a problem with a specific device or browser.
3. Contact the technical support team of Thailand TV Station and ask if there is a solution to a specific problem.
If none of the above methods can solve the problem, you can try to contact the technical support team of the video website or player to find out whether there is an option or solution for full screen setting.