I was running into an issue (#42136) where the networks you would try to add, would wipe out all other existing advertised networks. I believe it is safer to not automatically purge those networks and instead, have that as a option within the module itself. I have added networks_purge: as a boolean type.
I have never contributed here and can’t seem to figure out how to make a pull request as it seems I need to be granted access. Either way, within the issue linked below, I added the updated version of the code nxos_bgp_af.py which does not touch the existing networks unless requested. I updated the sub-module within nxos_bgp_af to also have a networks_purge: boolean type.
https://github.com/ansible/ansible/issues/42136
-hazelfire5