So this is kind of weird, and I'm not sure what the issue is, but when on some sites (I.e. Stack Overflow), the icons are incorrect.
The screenshot explains it better. Things look fine here on the Stack Exchange Meta, but on the Network Engineering site (for example) the icons for some sites are mixed up. (It does this for me for the drop-down list and HNQ lists.)
I've done a hard-refresh of everything, problem still persists.
Is this related to the new theme launch?