Having Windows & Linux Networking problems

[Terry N4TLF]

Ok, guys, I admit that I need help with this.  Sorry that this is long...

I am having Windows networking problems that have developed over time.  The 
N4TLF shack has several (at least ten) Windows and Linux computers, and one 
Macbook Pro.  These used to talk to each other via either wired gig-e (with 
D-Link switches), or wifi, but problems have developed.  At this point I am 
really confused.  Some Win10 boxes see only three other computers, some 
four, and two see all of them.

I wanted to add a new Octoprint/OctoPi server to my My new 3D printer.  I 
have used Octoprint before with Windows 10, but am now having no luck.  The 
goal was not to see the octoprint server using a browser, but to have a 
certain folder (watched) on the octoprint server show up in Windows Network, 
so I can drag and drop gcode files to that directory to automatically start 
a print.

I downloaded the latest Octoprint image, and installed it on a new Raspberry 
Pi 3B.  First problem was that "octopi.local" no longer works.  Fixed that. 
Next, the newer Octoprint images have samba turned off.  (Why do Linux 
people insist on screwing up working stuff???)  Fixed that.  I can now see 
and connect to the Octoprint server under browsers, and ssh via Putty.

Now, the Octoprint server does not show up on most Win10 computer under 
networking.   The Octoprint server IS showing up on an old laptop running 
Linux and the Macbook Pro as network devices.  Many of the Windows boxes 
also show up on both the Linux laptop and Macbook.

What's even worse is that many of the Windows 10 boxes do NOT show up on 
other Windows 10 boxes.  I actually have two Win10 laptops that see ALL 
other Win10 machines AND the Octoprint server.  Unfortunately, they are not 
the one computer that I need to see the Octoprint server.  I've updated ALL 
Win10 machines with the latest updates as of yesterday.

Of the several computers, I have two Surface Pro 3 computers that I have 
verified as having the same Win10 updates, same Network sharing and advanced 
network sharing options, same lack of McAfee, same firewall settings (OFF). 
One can see all nine Win10 boxes and the Octoprint server.  The other only 
sees four Win10 boxes, and NOT the Octoprint server.  Both of these are 
downstairs right now, both connected to the same wifi router, sitting side 
by side.  Other than different apps, I haven't found any differences between 
these two SP3s.

I saw that Microsoft totally screwed up Windows Networking with the April 
2018 (1803) update.  I've seen and tried a few "fixes" for this, including 
changing some system services to load automatically.  ALL my Win10 boxes 
have that specific fix, no difference detected.

Anybody have any ideas?  I MUST be missing something easy, but I cannot 
figure out what.

TIA & 73, Terry, N4TLF