Form re-submitting in Edge browser

I have a simple form one button and a gridview. When the user clicks the button their name and the time they clicked is logged. I am using a meta tag to refresh the page every 30 seconds. It works fine in IE, Chrome, and Firefox but, on Edge browsers when it refreshes it gives the user a pop up to resubmit every time to resubmit and logs them again every time.

<meta http-equiv="refresh" content="30" />
    <form id="form1" runat="server">    
    <asp:Button ID="btnSave" runat="server" Text="Pick Up"/>
    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
        <Columns>
            <asp:BoundField DataField="PLUSER" HeaderText="User" S 
             SortExpression="name" ItemStyle-Width="100px" />
            <asp:BoundField DataField="PLDATE" HeaderText="Date" 
             SortExpression="timeDate" ItemStyle-Width="250px" />
        </Columns>
    </asp:GridView>
    </form>

Is there a setting or something special about edge in relation to meta tags?