Can't connect to samba server over network

I posted some months ago about this problem, but didn't get a resolution, and the Covid-19 lockdown distracted my attention until now. Here's a link to the previous topic:
https://sfj48-fkj200.heiksthsd.cf/clearfoundation/social/community/i-ve-installed-and-configured-samba-in-the-very-limited-way-allowed-by-the-samba-configuration-settings-screen-but-can-t-connect

I still can't get a samba connection to my ClearOS server, which is set up to host a Plex Media Server. I've had a series of different problems connecting to the plex server to access and play my media, only just resolved.

So I'm coming back to the issue - how do I get Samba to work?

The last comment in the previous thread asked if I had set up Flexshares. The answer is 'I have' and there is one set up called <blockquote>plexmedia</blockquote>. In the ClearOS console accessed at 192.168.0.31:81, it shows


And the Samba configuration panel says:


Using ssh from the iMac Terminal, I can connect and browse the files on the ClearOS server using Midnight Commander, so on request I can look at the contents of (for example) files.

I've checked that the samba service is running:


When I try to access the files in <blockquote>plexmedia</blockquote> from Finder on my iMac, whether by <blockquote>ip</blockquote> address or <blockquote>//plexmediaserver/plexmedia</blockquote>, I just just get a timeout with error message.

Whey I try to access the server from Terminal using

I just get an error message: "no such file or directory."

I get the same result when trying to access the server from my Mac laptop instead of my iMac.

It's really annoying that I HAVE had this working in the past, on a previous standalone ClearOS server, whereas this one is a virtual machine running under VMware ESXi 6.5.

Any suggestions to diagnose and fix this problem will be very much welcome. I'm stuck.

I CAN upload files via FTP, but it isn't nearly so convenient, or as fast, so I'd really like to get SAMBA working if possible.