This is common issue because the PWA is not programmed to capture third party icons. So if you see this issue :
Capture the file path for the icon files
Locate the icons path. For exmaple, above icon set comes from following location.
elementor icon set
Now we need to insert this icon set into the PWA pre-cached resources.
After adding these paths , you will need to “Regenerate Service worker”
Then you will need to update the service worker in your own browser
