Featured Icons vanish in Safari

Customizing ? Landing Page ? Featured Icon Blocks

I’m using Featured Icon Blocks on my landing page. In Safari 13 (have not tested other versions), the icons themselves load fine at first, but when window is dynamically resized, the icons disappear entirely. They will not reappear until the window is refreshed or reloaded no matter what size the window is made.

All software is up to date.