Why are certain features not available for Glide pages?

[Jeff_Hager]

@Robert_Petitto here is an alternative to a progress bar.

<div style="overflow:hidden;border-radius:15px;background-color:#DDDDDD;"">
  <div style="border-radius:15px;background-color:#29577A;height:15px;width:33%">
  </div>
</div>