Mobile Site and Main Site Redirect Problem

I have a mobile site subdomain “https://m.airyougotravels.com/” and main site “airyougotravels.com”. I don’t have any problems with the main site. But when it comes to mobile site, every time I click a product, it redirects to “https://airyougotravels.com/product/3d2n-hong-kong-shenzhen/”. Also, when I try to make it mobile “https://m.airyougotravels.com/product/3d2n-hong-kong-shenzhen/” it says “Not Found
The requested URL /product/3d2n-hong-kong-shenzhen/ was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.“

You can try the Mobile site above to experience my problem.