LE settings (Samba server) completely independent of Kodi (Samba client, aka smbclient) settings. If Kodi min/max is set to none the defaults are effective, which means SMB2 thru 3 can be used by the client. In LE the Samba server also defaults to the same min/max values but that's a deliberate coincidence; client/server are different things.
Actually Kodi min/max when set to None means Kodi client will support SMB1 through SMB3. Since having a client that still supports SMB1 (even if the server doesn't) is at risk of man-in-the-middle connection downgrade exploitation the longer term objective (LE9 etc.) should be for the default Kodi client min/max to become SMB2/SMB3 rather than SMB1/SMB3.
Many clients should by now be compatible with SMB2, and SMB2 is generally considered to be free of the security flaws that blight SMB1.
It's probably worth pointing out that SMB2 isn't actually a specific protocol, it's (at least in the most recent versions of Samba, as provided by LibreELEC) a synonym/alias for the SMB v2.10 protocol, while "SMB3" is (currently) an alias for SMB v3.11 which is the latest version of SMB (there have been several versions of v3: SMB3_00, SMB3_02, SMB3_10).
Samba v4.0 introduced SMB2_10 support, and pre-v4.0 Samba servers that only support SMB v2.00 or SMB v2.02 may not be accessible by a LibreELEC Kodi client using "client min protocol=SMB2" as the client will start connecting with SMB2 v2.10, which will fail. In such a case it will be necessary to manually configure "client min protocol=SMB2_02" (or SMB2_00) in /storage/.kodi/.smb/user.conf.
It's also possible/likely that older versions of Samba (pre-v4.0) may use different values for the SMB2 alias, such as SMB2_00 or SMB2_02, and pre-v4.2 the SMB3 alias will not be supported at all.
What I'm saying is that the precise "meaning" of "SMB2" and "SMB3" will depend on the version of the Samba client AND the version of the Samba server, as either one could have a different understanding of what each alias means, which could result in an inability to establish a connection. You gotta love Samba, it's such a mess...
So anyway, just something to be aware of when setting SMB2/SMB3 all around, and you start getting weird results - try manually configuring a specific min/max protocol rather than using a potentially ambiguous alias.
Also, don't be surprised if Mac OS gives you problems - the Samba server provided by Apple is known to have several issues.
Samba is a bitch to cross-compile for different platforms so different versions of Kodi run different samba (smbclient) versions. AFAIK both MacOS and Android are still on 4.1 while Linux (depending on distro) will have newer things available - LE is using current versions and is quite advanced in this respect. Other iOS apps may use different SMB libs and not Samba or OS native functions. macOS uses its own SMB stack not Samba although there are legacy references to conf files. Combined .. it's a mucking fess.
use NFS if possible, solves a lot problems 
Christ - some standardization amongst the OS vendors would make life a lot frickin easier for devs and end users alike. That's just wild chewitt.
Yes! You get it! 
That's why we've tried to signpost the Samba changes in each release as best we could, and have been criticised for providing too much detail ("I don't want to read a wall of text"). We've been asked to post simple instructions but if it were possible to write "To get Samba working you need to do this, this and this, then sit back and relax", we would have. If we posted all the detail relating to Samba, most people would get a very severe headache (assuming they even read it!)
Once you understand how much of a mess Samba really, truly, is, it's clear that simple configuration instructions *that can work for everyone* are literally impossible to write as what needs to be tweaked within the network depends entirely on the equipment that each user may have in their network.
There's obviously Windows XP/Vista/7/8/10 and whatever protocol Microsoft are defaulting SMB to this week. There's Samba running on Linux/FreeBSD/Android, NAS and routers, which is often an ancient/insecure version such as Samba 3.6.y with maximum SMB2_02 support (and impossible to upgrade), or possibly 4.0 with SMB2_10, and maybe even 4.2 with SMB3_00. The more popular Linux distributions (eg. Ubuntu) haven't yet disabled SMB1 by default which leads to more interop compatibility issues when other vendors have disabled SMB1, but they should be doing so soon. And then there's whatever Apple call their half-baked Samba-like implementation on MacOS/iOS/tvOS. Getting all of this to work with a single, common protocol is... tricky.
When *everything* worked with SMB1 life was so simple (but scary)!
Maybe in a year or two when SMB2 is supported everywhere life will become a little easier (unless you own an Asus router, of course, in which case you should expect to get owned eventually).
This thread alone is a learning experience for me.
I posted on the forum with issues when 8.2 was released, and I'm guilty of not seeing the wall of text on day 1. (I installed the update within LibreELEC - that had quite a bit to do with it.) But after receiving a forum response, I read that wall of text. It's not really that much.
I've always been someone who reads release notes, though - except that time, of course. Even if I only understand 1/3 of the bullet points. I've learned things just from context reading release notes.
After the read, I resolved some issues that I had by teaching myself (I know - it's simple.) the relevant parameters to edit a copy of the samba.conf.sample file in /storage/.conf/.
Made some changes to the home items and made my version the live version. Easy.
Backed the edited version up too.
By the way, I can understand why (especially mainstream) Linux distros would retain legacy compatibility - Ubuntu wants to make moving from Windows or macOS as pain-free as they can, I'm sure.
What really bugs me is WHY Apple insists on making this ridiculous, unpredictable system (stack?). I'm serious - I'd like to know why. They TRY to give the impression that their OS is the easy-to-use alternative to Windows....
You could rename the thread to "Why there's no such thing as a simple SMB question"...
Same as no free lunch, I suppose.
I learned a bit too. I knew it was a bad state of affairs. I had no idea how bad. I guess I've been lucky.
This was a learning experience for me- and I did some repairs as recommended by the kind folks on this forum. Should have done awhile back, but now feel that browsing environment much more secure with no SMB 1 ..
