A lot of people suffer from missing icons in smartthings classic app after recent update.
I think the problem is from http/https policy.
Due to recent update of Smartthings classic app, along with new policy of android WebView of only allowing https, (except explicitly defined)
Icons do not appear in deviceTile in smarttings classic app.
For example, st.secondary.refresh is the frequent used icon, which is actually redirected to http://cdn.device-icons.smartthings.com/secondary/refresh.png
Since it is http, not https, the icon does not show in device tile.
Please fix this problem. Please the document below regarding the android’s policy