This hasn't been adequately answered in the community as yet.
For me, it happens randomly (today) no new software, changes to voice assistant, etc. Random network drop outs have been a proposed culprit, but why does it still work if I use the Alexa on my phone. This fact alone points to issues in Sonos - either the microphone is not picking up the question / statement being made to Alexa correctly, or other wiring/electronics issues. However more likely a sonos network issue, given that all sonos products with microphones are equally affected.
Any thoughts, brilliant experienced sonos community?