Character encoding issue when changing site url (on Azure)

I am hosting a WordPress site using Azure (with mySQL by clearDB), which can be found here:
https://parkwayplace.azurewebsites.net/

Everything looks fine, and it works with my custom domains, such as:
https://www.parkwayplaceevents.com/

(redirecting from the latter to the former)

Great!

However, when I change the “Site Address (URL)” setting (in General Settings) so that the user ends up at the latter URL, then I get some character encoding issues. (specifically, the Facebook, etc. logos in the upper right turn into squares)

I have read about utf8 vs utf8mb4 and believe my database is set to utf8. This sounds like the problem but I admit I was a little hesitant to follow the various directions I’ve found for updating my DB to utf8mb4; just a little beyond my current understanding.

Having said all that — if the DB encoding is the issue, then I can’t imagine why it only manifests when setting a different Site Address. Likewise, since everything displays fine on the initial URL, it leads me to believe that the DB encoding is *not* the issue to begin with.

Any help in troubleshooting this issue and allowing me to change the redirect target URL without losing the “special” characters would be greatly appreciated.

Thanks!