I currently have my profile picture set to either my Gravatar or my uploaded picture (which are identical), on my network profile (https://stackexchange.com/users/7121054/solomon-ucko) and the profiles for some of the sites (e.g. https://stackoverflow.com/users/5445670/solomon-ucko), but it shows an Identicon instead on most sites (e.g. https://english.stackexchange.com/users/146302/solomon-ucko), and I have to manually change it for each. "Save and copy changes to all public communities" does not appear to help. All the sites had my custom profile picture initially; I think I first noticed this issue after enabling Dark Mode on Stack Overflow, but it could be completely unrelated. Is there any way to fix this without manually fixing each site? This also appears to be an issue for newly created accounts.
This has been answered in Profile avatar lost on several sites after profile edit (Gravatar replaced with Identicon): upload a new (possibly identical?) profile picture.