Playlists lost (after update I guess)

Sounds like you did a factory reset or chose 'new system' somewhere. All the config data is replicated across all your Sonos devices, but as it appears you had a full system reset then it is likely all gone. You could try crossing your fingers and rebooting them all, to see if it is a transient issue, but the odds are not in your favor.

Hi Controlav. Alas I didn't knowingly choose 'new system' nor do a reset. All that's changed recently is that we have a new broadband provider and that seemed to force loads of setting up on Sonos. I've been a long time user of Sonos but am losing faith in it as it constantly seems to need updating and dropping speakers. Shame. It was good when they kept it reliable and simple.

Changing router is a simple matter, but unfortunately it isn't uncommon for people to think they have to set up their system from scratch. The fact that you talk of setting up at all makes me think that it must be what has happened. That's a shame.

FWIW, most of my phone apps seem to update far more frequently than Sonos.

https://support.sonos.com/s/article/1061?language=en_US

Hi John. I'm pretty IT savvy so not easily fooled by simple router changes, but sometimes I lose the will to live as various Sonos controller updates disappear into iterative loops! So I too suspect that this one got by me and did lose all my playlists. Shame. I agree about the other numerous app updates, but very few lose as many settings and 'data' as the Sonos updates do. I'm patient, but a bit exasperated!

I've found setting static/reserved IP addresses for all my Sonos devices in the router's DHCP pages ends a lot of the update related strangeness.

Hi John. I'm pretty IT savvy so not easily fooled by simple router changes, but sometimes I lose the will to live as various Sonos controller updates disappear into iterative loops! So I too suspect that this one got by me and did lose all my playlists. Shame. I agree about the other numerous app updates, but very few lose as many settings and 'data' as the Sonos updates do. I'm patient, but a bit exasperated!
I think you are talking about the speaker/room 'queues' here, rather than 'playlists', which are normally saved somewhere, such as within a streaming music service, local library, or the 'My Sonos' tab etc.... I would not rely on using the 'queues' as 'playlists', as they are easily over-written and lost sometimes via power outages etc.

I would suggest saving your 'playlists' and that way, they are easily and quickly recalled. It’s also a good thing to reserve the Sonos IP addresses in your routers DHCP Reservation Table, as Stanley_4 suggests in his post above. I haven’t had a problem with a Sonos update either since doing that.

Thanks Stanley - that's a really good suggestion.
Hi Ken. No, I wasn't talking about queues - I'm referring to genuine Playlists. We had them all stored as 'Sonos Playlists' and they no longer appear on any of the family mobiles, nor our house PC, nor our tablets. I just assumed these were server based lists linked to our registration, as obviously they can't be stored locally! So I remain puzzled as to why they've disappeared.

One thing to remember once you carefully assign static/reserved IP addresses to your Sonos gear, if your router also allows you to assign names that will make some troubleshooting tools easier to use but Sonos still requires access by IP address to avoid potential name based attacks. So when you forget this and try to access SonosZP5-E2.home and the web interface barfs at you, recall I warned you!