Hi,
could you please check if you set
DelayedLoading="true" attribute in the repeater control?
If the attribute is not available you could try to add following code into your Page_Load method:
protected void Page_Load(object sender, EventArgs e)
{
//repItems = ID of your repeater
repItems.DataBind();
}
If it does not help, could you please share the code of webpart with us?
Best regards,
Ivana Tomanickova