The html line with the {data: room} values, appears double in the email

I used the dropdown field with the multi select option and received the {data: room} double. It also adds this line to the bottom of the email although this is not present in the template.
Why?

Hi Fritz,
​
You have the Data Setting 'Include value in email' enabled, please try turning that off if you are using an email template.
​
Bob

Without the option "Include value in email", this value is not reported in the email, despite the email template code (below) this comprised!
​

<table width="100%" cellpadding="3" cellspacing="3" border="0" class="ui table">
<tr><td width="30%" valign="top" align="right"><strong>name surname</strong></td><td width="70%" valign="top" align="left">{data:name_surname}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>e-mail</strong></td><td width="70%" valign="top" align="left">{data:email}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>your telephone or mobile</strong></td><td width="70%" valign="top" align="left">{data:telephone_or_mobile}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>room</strong></td><td width="70%" valign="top" align="left">{data:room}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>persons</strong></td><td width="70%" valign="top" align="left">{data:persons}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>children</strong></td><td width="70%" valign="top" align="left">{data:children}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>arrival</strong></td><td width="70%" valign="top" align="left">{data:arrival}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>departure</strong></td><td width="70%" valign="top" align="left">{data:departure}</td></tr>
<tr><td width="30%" valign="top" align="right"><strong>comments</strong></td><td width="70%" valign="top" align="left">{data:comments}</td></tr>
</table>