Problem with colour inheritance

In a Figma library file, we have an icon set as separate components. The icons are multiple shape objects, i.e. they are not compound paths. All the icons should be monochrome in any state.

If we replace one icon(component) with another only parts of the icon will inherit the colours from its replacement. The rest of the icon shapes will pick their colour from the colour applied to the icons as Main Components. Can anyone help with troubleshooting this or confirm that this is a bug?