Dear, I have a RPi 3B+ and router not connected to external network, I have just configured SMB. I can to connect my RPi through FileZilla (sftp://192.168.1.2/ user, password and port 22), but if I try to connect through Windows SMB network. Why?
Ping to RPi is ok.
Connection Putty is ok.
I explain better, I have a new router just connected and not configured not connected to the internet, from the settings I see that the RPi is connected with its static ip. I want to use raspberry on the internal network. This raspberry is tested. I used it in another network (connected to the global network) and the internal network. I was able to reach it without problems from all the PCs with the configuration of the screenshot above.