Ever since the new Echo notification menus are in use (where you have two separate menus for alerts and messages), when you click on the menu to open it, the number it shows snaps from the localize number to the English number. For instance, on Fa WP if you see "۰" (Persian zero) and click on it, it changes to "0" (English zero). See screenshot.
I suppose it is because JS tries to update the number, but fetches it from a source that is not localized (or fetches it as a numeric value, but forgets to localize it).