Since the deprecation SMB1, Microsoft has started to rely on WSD - Web Services for Devices to locate SMB servers and shares on the local network. Samba does not support WSD which means that Samba shares does not show up in Network browsing from Windows clients.
I have tested https://github.com/christgau/wsdd a python implementation of WSD that works good. It requires no dependencies other than Python3.
A quick search shows other candidates:
https://github.com/Andy2244/wsdd2 - an implementation used by OpenWRT
https://github.com/kochinc/wsdd2 - an implementation for OpenMediaVault
Many ebuild requests remain open for years, because nobody maintains the package.
If you want to be (proxied) maintainer of this package, please contact the proxy team  and prepare an ebuild .
You may want to link your repository  or attach the ebuild here until it makes its way to the official tree.
Created attachment 573174 [details]
This is an initial ebuild which is tested on an AMD64 arch with Python3.6.
Source is available on GitHub: https://github.com/Gatak/wsdd-ebuild
Good news! The author of wsdd has created a repository on GitHub with his own Gentoo ebuild. :)
It is available at https://github.com/christgau/wsdd-gentoo