Textboxes and Dropdown appearing when visibility set to false - asp.net

Question

We have a page that allows users to update data using about a dozen textboxes and several dropdowns. Half of all the fields are permanently visible and the rest are hidden. If a checkbox is checked, the page reveals the rest of the fields.
When first arriving on the page, the two textboxes and dropdown in question are not visible, along with the rest of the fields not visible, unless the checkbox is checked.
However, with the update functionality (a button click) the two textboxes and dropdown appear with the other permanently visible fields. Oddly enough, the labels corresponding to the fields that should be hidden do not appear. Another point is that, if the checkbox is checked and then unchecked, the fields in question are not visible.
So it appears that the issue is with the update functionality but we haven't been able to pinpoint what the issue is. We have tried setting the visibility to false in the .ascx.cs file but that has had zero effect along with other things we've tried.
Is there anything obvious we might be missing from our code below?
ascx:
<asp:FormView ID="FormView1" runat="server" DataSourceID="odsQWER" DataKeyNames="Oid"
OnItemInserting="FormView1_ItemInserting" EnableModelValidation="true"
OnItemUpdating="FormView1_ItemUpdating">
...
<tr>
<td style="width: 200px">
<asp:Label ID="ContactFNameLabel" runat="server" Text="Vendor Contact (First Name):"
Visible="false"></asp:Label>
</td>
<td>
<asp:TextBox Width="400px" ID="ContactFNameTextBox" runat="server" Text='<%# Bind("FirstName") %>'
Visible="false"></asp:TextBox>
<asp:RequiredFieldValidator ID="ContactFNameValidator" runat="server" ControlToValidate="ContactFNameTextBox"
Display="Dynamic" ErrorMessage="Contact Name cannot be Blank" Visible="false"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td style="width: 200px">
<asp:Label ID="ContactLNameLabel" runat="server" Text="Vendor Contact (Last Name):"
Visible="false"></asp:Label>
</td>
<td>
<asp:TextBox Width="400px" ID="ContactLNameTextBox" runat="server" Text='<%# Bind("LastName") %>'
Visible="false"></asp:TextBox>
<asp:RequiredFieldValidator ID="ContactLNameValidator" runat="server" ControlToValidate="ContactLNameTextBox"
Display="Dynamic" ErrorMessage="Contact Last Name cannot be Blank" Visible="false"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td style="width: 200px">
<asp:Label ID="CountryLabel" runat="server" Text="Country:" Visible="false"></asp:Label>
</td>
<td>
<asp:DropDownList Width="405px" ID="CountryDropDownList" runat="server" AppendDataBoundItems="true"
DataSourceID="odsCountry" DataTextField="Name" DataValueField="Oid" SelectedValue='<%# Bind("CountryId") %>'
Visible="false">
<asp:ListItem Selected="true" Text="<--Select Here-->" Value="0"></asp:ListItem>
</asp:DropDownList>
<asp:RequiredFieldValidator ID="CountryValidator" runat="server" ControlToValidate="CountryDropDownList"
Display="Dynamic" ErrorMessage="Country Must be Selected" InitialValue="0"></asp:RequiredFieldValidator>
</td>
</tr>
...
<asp:Button ID="UpdateButton" runat="server" CausesValidation="true" CommandName="Update" OnClick="btnUpdateClick"
CssClass="button" Text="Update" Visible='<%# true %>' />
...
<asp:ObjectDataSource ID="odsQWER" runat="server" InsertMethod="AddRequest"
TypeName="BLL.TESTRequest" SelectMethod="GetRequest" OnInserting="odsQWER_Inserting"
UpdateMethod="UpdateRequest" OnUpdating="odsQWER_Updating" OnInserted="odsQWER_Inserted"
OnUpdated="odsQWER_Updated" OldValuesParameterFormatString="{0}">
...
aspx:
protected void btnUpdateClick(object sender, EventArgs e)
{
CheckBox chk = (CheckBox)FormView1.FindControl("IsNewCheckBox");
FormView1.FindControl("ContactFNameTextBox").Visible = chk.Checked;
FormView1.FindControl("ContactFNameLabel").Visible = chk.Checked;
FormView1.FindControl("ContactFNameValidator").Visible = chk.Checked;
FormView1.FindControl("ContactLNameTextBox").Visible = chk.Checked;
FormView1.FindControl("ContactLNameLabel").Visible = chk.Checked;
FormView1.FindControl("ContactLNameValidator").Visible = chk.Checked;
FormView1.FindControl("StateDropDownList").Visible = chk.Checked;
FormView1.FindControl("StateLabel").Visible = chk.Checked;
}