Comment 33 for bug 1828107

My apologies for sidetracking this far trying to explain differences between discovery and browsing but there seems to be a lot of mixing the 2 as one. The fact that you have "discovered" a server you wish to "browse" is irrelivant for this bug (afaik you shouldn't have been able to discover it as there are currently no working mechanisms to do so in LTS versions judging from the open bug reports). If however you are experiencing a crash whilst attempting to browse a share of the discovered host, that is relevant and is to do with the way SMB protocol versions themselves are being handled.

WRT the rest of the discussion:

SMBv1 leveraged NetBios to do discovery, (as did WINS which was a fallback discovery method). With SMBv1 removed/disabled, all of the NetBios discovery is also removed/disabled. Therefore, a discovery protocol is needed. Enter WSD. SMBv2 and SMBv3 use WSD to discover hosts on the network, (incidentally WSD was designed for SMBv2 during the development of Vista to remove the dependancy on NetBios).

If you know the address of a host serving SMBv2 or SMBv3 already (via WSD, any other discovery protocol, off by heart), you can just do an SMB request against that address:
smbclient --list=<<SERVER>> --user=Anonymous -N

>The discoverability and connectivity works when the process is terminated and restarted. Clearly this is achievable.
> Yes, netbios was used previously, but clearly after killing the process I can reach them without SMB v1, just not after the first boot.

This is still probably nothing more than a cached entry, start-up check of previously known hosts, or initial broadcast. Some of which may or may not be unintentional from a security perspective, so as @seb128 said, file another bug report against them if you so wish.