This is my blog: http://nghiepnguyen.xyz/blog/
it use Activello Themes.
I do not know why mobile interface unlike demo in wp admin setting.
Hi @chuchuottui1987,
I hope you are well today and thank you for your question.
This can be Jetpack plugin issue if you are using on your site so please make sure you are not using its Mobile Theme functionality Mobile Theme which may be causing this issue.
Best Regards,
Movin