I have Amazon echo devices in almost every room of my house (7) and they're all connected on a multi-room group. Whenever I tell Alexa to play Pandora on the Everywhere group, it will play for about 5 minutes then about half the speakers will randomly start playing a different song. If I do nothing, after a few minutes the other speakers then switch and join with the new song. It happens repeatedly if I leave them on for awhile. This problem just started recently. I stopped listening to amazon music because it caused other problems (mostly just stopped playing). I was told by Amazon that it was my wifi but I've had the same wifi setup for 3 years. Most problems with multi-room music started a few months ago. I'm about ready to get rid of all the amazon speakers but really want to be able to listen to music everywhere. Any suggestions? Is it me or Amazon or Pandora? Why wouldn't it work anymore?