CRM15: web page html source code is updated after publishing even though I didn't make any change on the code?

Hello,

I have a weird issue I found today. I have a web page embedded on form. when loading form, the web page data will be loaded as well. this is what it supposed to display:

however, the data is not loaded after publishing this web page as follow:

Then, I check the source code, I found the html file is automatically changed even though I didn't make any changes. it changes the first line of html

from:

to:

this section 

<meta charset="utf-8">

is automatically added after publishing. and my 'OnLoad' function in JavaScript is not triggered.

my question is why this happened? how to prevent <meta charset ="utf-8"> being added?

Thanks.