Sonos tech support advice: “buy a new router or hard wire the blue tooth speaker 
♂️. Obviously the speakers are not stable. speakers go t1ts up every time the App updates and they regularly drop out. Takes ages to “turn off the on again” and the speakers struggle to find the network.
Sending the 100’s back along with speaker stands.
Probably our last ever purchase from Sonos.
All our other WiFi / blue tooth tech works fine.
When Sonos devices update their firmware, they then follow the update with a reboot to load the new firmware. This reboot also requests a new network IP address from your router. This request can cause issues for Sonos devices due to the added complexity of the multi room connectivity.
The advice from Sonos tech support was probably intended to test if this was the cause of the issue before suggesting a resolution. If you are interested in resolving the issue, you may want to read my post:
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