I haven’t the faintest idea. The container is using flexbox, which is supported by all major browsers. Unfortunately we can’t really help if we can’t recreate the issue on our end. Possibly reach out to the developer of the theme and see if they can help.
I appreciate you letting us know which theme you are using as well as providing screenshots. Since the theme Organix is a third-party theme, we are a bit unfamiliar with the format of the coding used. I would suggest in this case, reaching out to the developers that designed and support the theme. They should be able to provide you with some additional support to making this coding change on the theme.
It may be worth attempting to clear the cache on your browser to see if that allows the icons to display correctly. If the issue persists, you can then try this on separate browser - as for example, if you are using Safari try this action on Google Chrome.