Icons Frequently Don’t Appear and Show Box Instead

Hi there, I’m having an issue with the Sepetra theme, where the site is often missing any of the icons from the theme. For example, instead of the search box on the menu in the upper right, it shows this square box:

Also, and more noticeable is the icons that should be in the featured icons are instead showing square boxes:

I even see the same when I’m in the theme options where you would choose/change the icons to use:

This doesn’t happen ALL the time, but about 25% of the time and it will usually load correctly if I refresh the page several times. I have removed almost all other plugins to troubleshoot – the onlye ones left are the same I use on all my other sites that are working w/o issue. I have used the Septera theme for several sites and never run into this issue – in fact, they are all loading fine when I test them now on the same hardware behind the same firewall so I do not suspect an issue there. I’m on WordPress 6.7.2 and Septera 1.5.1.1. Any ideas? Thanks and have a good one,
Chris

Website: cardsota.com