I am using GrapheneOS. GrapheneOS has a compatibility layer providing the option to install and use the official releases of Google Play in the standard app sandbox.
I could see how they are blocked on your system, using GrapheneOS, but that doesn't tell us if Netguard blocks them on Android systems. One reason for GrapheneOS is to close that kind of hole.
I am using GrapheneOS. GrapheneOS has a compatibility layer providing the option to install and use the official releases of Google Play in the standard app sandbox.
See https://grapheneos.org/features#sandboxed-google-play
NetGuard also shows network requests from GrapheneOS itself, all proxied by the GrapheneOS project, as described here: https://grapheneos.org/faq#default-connections
I could see how they are blocked on your system, using GrapheneOS, but that doesn't tell us if Netguard blocks them on Android systems. One reason for GrapheneOS is to close that kind of hole.