What did Sonos Support say, when you called in to to discuss it?

Unfortunately, I traded in my PLAY:5 gen 1s years and years ago, so I can’t test anything to help.

They said you have failure in power amp .

I felt that for two speakers to go at the same time when the app had been updated ,seemed to me that the app was at fault and NOT the power amp.So I waited and waited for the app to be updated . Hasn't happened on android yet

They have much more access to hard data than the rest of us do, it’s hard to compete. If they say there’s been an electronics failure in the Sonos Amp, it’s hard for this community to come up with a better answer. Given that they say there’s been a failure in the Amps electronics, I wouldn’t expect any changes in the next Sonos firmware release, But YMMV.

For Playback, the Apps tell the speaker which tracks to play, not much more. 

To be clear though, are you saying if you initiate the music from an iPad it's OK but from Android it's distorted - for the same music etc. yes? 

Once the update on S1 on Apple iOS took place ,the horrendous distortion disappeared and played music ,perfectly 

I then went back to the Android app and everything is fine .A day earlier ,it did NOT

Since the controller (iOS or Android) is merely a remote control that tells the system on the speaker what to do, it’s really challenging to believe it would have any impact. I’d certainly suspect something else is going on, like a randomly occurring failure within the speaker, which the Sonos folks suggested. 

Well whatever it is .for the first time in eight months ,I'm listening to both the speakers.It is not as if I've forgotten about them for eight months ,I've checked them once a month even yesterday.no change .Then I thought try the app on apple and it says,in the app store update .So I retried them and they worked ,without muffles sound.I was happy . Bye for now