Master - Detail Gridview column hiding Devexpress - devexpress

Question

I have a multiple Parent-Child Gridview. The problem is Parent gridview Column name is Cost ($) and the ($) symbol is hiding when i expand the Child gridview and get it back when i minimize the Child gridview (Devexpress). The Parent-Child gridview is present in the AspxCallbackPanel and in the PopupControl.
<dx:ASPxCallbackPanel ID="cbpCartDetails" runat="server"
OnCallback="cbpCartDetails_Callback" ClientInstanceName="cbpCartDetails">
<ClientSideEvents EndCallback="cbpCartDetails_EndCallBack" />
<PanelCollection>
<dx:PanelContent ID="pnlCartDetails">
<dx:ASPxPopupControl ClientInstanceName="popCartDetails" Width="600px"
Height="250px" CloseAction="CloseButton" MaxWidth="800px" MaxHeight="800px"
MinHeight="150px" MinWidth="150px" ID="popCartDetails"
HeaderStyle-ForeColor="White" HeaderStyle-Font-Bold="true"
runat="server" EnableViewState="false" PopupHorizontalAlign="WindowCenter"
PopupVerticalAlign="WindowCenter" EnableHierarchyRecreation="false"
Modal="true">
<ContentCollection>
<dx:PopupControlContentControl ID="PopupControlContentControl2"
runat="server">
<dx:ASPxGridView ID="grdBuildingCartEst" Width="100%"
Theme="SoftOrange" KeyFieldName="CarttypeId"
ClientInstanceName="grdBuildingCartEst">
<Columns>
<dx:GridViewDataTextColumn FieldName="CartType" />
<dx:GridViewDataTextColumn FieldName="NumberOfCart" />
<dx:GridViewDataTextColumn FieldName="Cost" />
</Columns>
<Templates>
<DetailRow>
<dx:ASPxGridView ID="grdFloorsCartEst"
Width="100%"
Theme="SoftOrange"
KeyFieldName="CarttypeId"
OnInit="grdFloorsCartEst_Init"
OnBeforePerformDataSelect=
"grdFloorsCartEst_BeforePerformDataSelect"
ClientInstanceName="grdFloorsCartEst">
<Columns>
<dx:GridViewDataTextColumn
FieldName="CartSize" />
<dx:GridViewDataTextColumn
FieldName="NumberOfCart" />
<dx:GridViewDataTextColumn
FieldName="Cost" />
</Columns>
</dx:ASPxGridView>
</DetailRow>
</Templates>
<SettingsDetail ShowDetailRow="true" />
</dx:ASPxGridView>
</dx:PopupControlContentControl>
</ContentCollection>
</dx:ASPxPopupControl>
</dx:PanelContent>
</PanelCollection>
Screen shot 1
https://i.stack.imgur.com/Fb1QX.png
Screen shot 2 (Error)
https://i.stack.imgur.com/AghdG.png

Answer 1

notice, in the code you've posted, there is no "Cost ($)" string for the master grid column, only FieldName="Cost". Most probably "Cost ($)" is set to column header at codebehind during Page_Load or some other event.
When you expand the child grid there happens a callback and the event code at codebehind where you set Cost ($) is not executed. So, you need to make sure the column header of the master grid is set to "Cost ($)" during child grid expand callback. To be 100% sure, post/attach the codebehind part of your page/control to the question's text.