Textarea field trigger change when not changed

Hello, I have a problem: textarea field which contain xml string "changed", when I even not touch it.
I change another field, but xml field also included in edit request from backend. It's inline editor and submit: 'changed',
My settings

let editorOptions = {
    ajax: ...
    table: '#tableEditor',
    formOptions: {
      inline: {
         submit: 'changed',
         onBlur: 'none',
      }
    },
    fields:
    [...,
       {
          "getFormatter":    function (val) { debugger; return val; },
          "label":"xml",
          "name":"xml",
          "nullDefault":true,
          "setFormatter":    function (val) { debugger; return val; },
          "type":"textarea"
       }
    ],
};

Xml, that I have in field, but not even touch (Same format with tabs and whitespaces)

<style type="text/css">email
            * {font-family:Verdana; font-size:11px;} 
            table {border:1px solid #888888;width: 100%;table-layout: auto;margin:0;}
            td, th {border:1px solid #888888; padding:2px 7px 2px 7px;}  
        
            .err {background-color:#ffcccc;}
            .errhead {background-color:#ccffcc;}
            .disk {background-color:#fff0aa;} 
            .nonDel {background-color:#ff0000;}
            </style>

I compared income and outcome values by get and set formatters and they are identic.
Can it be problem in textarea tag or I need to make some additional config?
Thanks