I'm going crazy over this as well.
I have windows 10 with my share folders upstairs with intel nuc with libreelec 8.2 downstairs. When I try to browse for samba shares it doesn't even see any. Not even libreelec's...
Is there an alternative to samba?
Did you read this entire thread. I had the exact same issue as you and it's fixed now. Your Windows 10 shares must have a login and password assigned. In Kodi, edit the source for your media and click browse - go to the bottom of the list to add network path (or something like that). Then add your Windows 10 IP address (192.168.x.x) where it asks for network share name. Add the name of the share path (videos, movies, etc) and then the login and password for the shares. You may have to edit the Windows "share with" to include the login name for the shared paths. Yes, I stumbled trying to figure this out too - even with help. A clear step-by-step guide or YouTube video would really be helpful.