代码未在线插入表格

I have a WordPress blog and a website to make notes. Both websites are on the same server using shared hosting. Both website have a separate database. I am inserting in table with the code below:

class cart extends horse {
    public function get_breed() { return "Wood"; }
}

class horse extends animal {
    public function get_breed() { return "Jersey"; }
}

class animal {
    public function get_breed() { return "Jersey"; }
}

But it is not getting inserted. When I click the submit button, it is just loading. I have inserted that code on local its working fine.

There are many codes I have, data is getting inserted properly on local but since I have made my website on online on shared hosting, I am having issues sometimes (not for all code): data is not getting inserted. Please advise.

The behavior is for both sites. Both sites will not get particular code.