Adding a full stop to the start of a component name makes that component hidden from publishing to the library. If you try to export one of those icons you get a system warning that files beginning with β.β are reserved for system files. But if you bulk export many of these at once, the popup does not show and the export completes successfully (although you wonβt see the files after export).
Unless there is a common use case for exporting a component from figma as a hidden system level file, perhaps Figma could automatically strip leading full stops from file names, both when exporting a single component and also when bulk exporting many?