unable to map \\umbrel2.local\music to my Sonos

The software version isn't very important, the SMB version is, that will be 1, 2 or 3.

If you are on the S1 Sonos software you need the SMB 1, S2 will work with 2 or 3.

https://support.sonos.com/en-us/article/add-your-music-library-to-sonos

Try it without the “.local”.  \\umbrel2\music or //umbrel2/music depending on which controller you’re using. If that doesn’t work, see if using the ip address works. //xxx.xxx.xxx.xxx/music

Definitely try using the IP, Sonos has had some inconsistencies with share names for a while now....

Thanks for your quick replies. Much appreciated. 
I have mapped the Umbrel2.local to a windows pc and it works. I have also tried multiple variations of ip vs umbrel2.local vs umbrel2. 

I have 2 play:1 speakers, where one is from 2013 and the other is from 2018.
Could that be the issue it is too old to have SMB3? 

Which Sonos software are you running S1 or S2, that matters (see my earlier post) not directly the speakers.

Some Sonos speakers only run S1, some only S2 and some both but it is the software that matters here.

The version of SMB on a speaker is, as ​@Stanley_4 suggests, not so much a function of the age of a speaker, but what operating system it is running. The Linux kernel of S1 can only handle SMB v1, but the Linux kernel of S2 can handle SMB v2x and above, but not SMBv1.

The Sonos app I use is S2 on an Android Phone. 

This likely explains it: use the Windows app to set up the share.

I dont understand why that would explain it. Is it due to its on an Android?

I have tried to install the app on Windows and do the mapping, but the results are the same. I will try this again with all thinkable combinations suggested as to ip address, umbrel2, umbrel2.local. There might have been some of them I did not try on the Windows app.