The past week I got a new android tv box. Like a phone, you have to replace them every few years. But I was having a lot of trouble with kodi and samba, especially connecting to my 'bleeding edge' computer.
So, I tried Plex as a media server, and it was good for 1080p, but died with 4K. My smb mounts worked great on my high-speed ethernet.
Back to Samba, and I found that everybody had trouble when their Linux upgraded. Finally I found that you have to completely delete your /etc/samba. Then there is a new one in /usr/share/samba. Just do a very simple share, and don't use gadmin-samba, since it is locked into smb2. Everything worked for me, including browsing, which I thought was lost forever.
For all the trouble I had, I have hung onto this line
force directory mode = 2770
in the shares section. It makes it public because the old 'public' is gone.
restart, and run testparm which is good to check things.
Now with your android box, you should be able to browse samba and see the shares.