1. You have mentioned in the query as “any controls”, whether you have mentioned Syncfusion controls alone or any other controls.
2. If you are using Syncfusion controls then share us the details of the controls in which the values get vanished after every post back.
For now we have checked the Grid control (with main features like Grouping, Sorting, Paging and Selection) and Tools controls with server side post back. Its working fine for us.
Please let us know if you have any queries.
<ej:Grid ID="Grid1" AllowPaging="True"
AllowReordering="false" Locale="en-US" AllowMultiSorting="false"
AllowSelection="True" Selectiontype="Single" OnServerRowSelected="DefaultEvents_OnServerRowSelected"
. . . . . . .
thanks, this helped me.