It looks like you had this issue a year ago. Which troubleshooting advice did you follow at that time? What happened when you submitted a diagnostics to Sonos?

The usual reboot players and router log out log in of sonos clear something within Spotify - Sonos technical changed my settings on my router, seamed to be ok for a bit but reverted back to music loss. I have a playbase setup to 2 x play 1s and a connect all within a 10 meter radius of my boost and I don’t seam to have issues with them. 
The 2 ikea symfonisk have been bad ever since I purchased them I really should have took them back. 

In that case, it sounds like maybe a wifi or network issue. Are the Symfonisk speakers wired or wireless? On wifi or SonosNet? 

All on sonosnet, just weird how playbase and connect have always worked fine. BT Wi-Fi strong signal everywhere always above 50mbs. 

Because Sonos is streaming a continuous music signal in data packets, it only needs a small error to potentially drop a speaker. A computer or phone doesn’t care about an internet page or suchlike not being sent/received or having to repeat in quite the same way.  

Does your wifi use any hubs or just the single unit?

is your wifi locked to one of the channels 1, 6 or 11?

Is your SonosNet locked to a different one of those 3 channels?

Have you tried moving the Boost closer to/further from any working speakers?

It’s Wi-Fi complete with one Wi-Fi disk, yes moved boost closer and currently sonos is on channel 6 and router is on channel 1.

Sorry: that’s not very clear.
What do you mean by “Wi-Fi complete with one Wi-Fi disk”? Just the hub? Hub and one repeater? If the latter, are they both locked to the same channel?

Are you saying you are now trying repositioning the Boost, or that you already tried that? 
 

Have you tried temporarily putting the Symfonisks in the same room as the Playbase?

Have you tried running them on Ethernet?

I was assuming that “Wifi Complete” was some sort of brand name I’d never heard of…..

Yes BT is the broadband supplier and the complete - is the package which yes comes with a disk (extender) which should mirror the existing settings from the router. Already tried and moved the boost closer. I also tried running my play 5 on Ethernet after speaking to sonos technical but that was still the same as before. I will try running the symfonisks on Ethernet after sitting them by my playbase. Thanks I’ll keep you updated. 

Check to be sure the disk is locked to the same channel. If it’s on an Auto channel selection that could be your solution. 
When you try the symfonisk in the same room as the Playbase, try them on wifi first. If they work there it suggests the signal isn’t reaching them in their normal location. 

Had both symfonisk speakers running next to my playbase for over 4 hours no drop in music, so that’s one issue resolved. Any suggestions on how to improve signal or is it down to the distance of my boost ? 
Now for the play 5 that’s about 3 foot away from the boost but has constant music drop outs, when you look on the app it still shows the track playing and the seconds counting down but no music. Sometimes restarts itself or you have to pause and play again but comes up with unable to connect with sonos. Close app and reopen and I let’s you restart ? 

If they work in that temporary location it does add to the belief the strength/reliability of the wireless signal isn’t getting to them in their normal location. 

I don’t know the layout of your home, the location of your speakers, or the construction material for the property. Start with this: What are the “distances” and walls/obstructions between each of Playbase, Play:5, Boost, and Symfonisks? Do you have any other Sonos components? Where are they located? Which are Ethernet wired and which are on SonosNet?

For a moment I’ll assume the Play:5 is closer to the Playbase than the Symfonisks. 

If you move the Boost closer to the Playbase does that help the Play:5, even if the Symfonisks get worse? Or, if you move the Boost into a different room from the 5?

If that does get the 5 working, the nature of SonosNet might then help the Symfonisks.

If not, is there any way you could at least temporarily run an Ethernet cable to one of the Symfonisks or the 5 in their normal location, to see what happens? 

Just to add: it might also be worth doing a complete system restart. Power off all your Sonos components, and the router and the hub. Wait for a few minutes. Then restart the router. When it is fully restarted and broadcasting wifi, restart the hub. When it is fully running, start the Playbase or whichever is wired to Ethernet. When it’s running, start any other wired devices one at a time, and then start the Boost. Keep going with each Sonos speaker, one at a time. That should ensure that their are no duplicate IP addresses, which can also cause issues. 

Thanks I’ll try all that 

Hi I’ve moved things around and added another Wi-Fi disk to my network and by doing this has improved connectivity and playback by about 90%, I still get a lot of dropping from the play 5 but yesterday I had Amazon music playing for 5 hours plus on my system with no music drops at all ? Any suggestions ?