Due to IWP files being cached, font awesome icons will not load on your IWP admin panel.
You can fix this issue by clearing those cache files.
IWP cache files can be cleared in 2 ways.
First is by running the below URL on your browser.
Note: Replace Your IWP URL with the URL of your IWP admin panel.
Second is by deleting the cache folder under IWP root folder/uploads/cache
If the same issue persists then try clearing your Browser cache and load your panel.