How to deal with a change of Radio Button selection after navigating back?

Question

I have a set of RadioButtons in a repeater. Once a RadioButton is checked, the related repetition is determined in a loop through its items and a parameter is saved to a Data Base. This triggers the loading of the next question with a new set of RadioButtons is. So far so good. If the user navigates back to the previous question then he could post a new selection and mess up everything. To deal with this unwanted operation, I wrote this code for the RadioButton OnChecked event:

• All repeaters Radio Buttons are first set back to unchecked and then the latest selection restored with ((RadioButton)sender).Checked = true.

• Afterwards I determine the related parameter and overwrite the already existing record for that question with the new value.

    protected void RB_Checked(object sender, EventArgs e)
    {
        for (int i = 0; i <= RPT_DisplayInquiry.Items.Count - 1; i++)
        {
            RadioButton rb = (RadioButton)RPT_DisplayInquiry.Items[i].FindControl("RB_Choice");
            rb.Checked = false;
        }
        ((RadioButton)sender).Checked = true;
  
        for (int i = 0; i <= RPT_DisplayInquiry.Items.Count - 1; i++)
        {
            RadioButton rb = (RadioButton)RPT_DisplayInquiry.Items[i].FindControl("RB_Choice");
            if (rb.Checked == true)
            {
                try
                {
                    string Choice = Convert.ToString(i + 1);
                    Label lbl = (Label)RPT_DisplayInquiry.Items[i].FindControl("Lbl_Structure");
                    SaveSelection(lbl.Text, Choice, 0);
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
        }
    }
  

For some reason this doesn't work. If I navigate back again after the new selection is saved, I see that the reset had not worked and that 2 RadioButtons are selected. Therefore the saved value is not necessarily correct as it is just related to the first found checked RadioButton in the repeater.

If I eliminate the call of the Save Routine from that methode and call it afterwards from a separate click event then the whole thing works.

Does the reset of the RadioButton not work as they are never rendered? What is going on?