Vocals on Era 100 Sound Bad

I saw a topic of this name and am experiencing the same issue. I bought a Sonos Era 100 to replace a Sonos One SL in my system. But the sound produced by the Era 100 is worse than the One SL. Vocals and mids sound muffled. I have tried messing with the equalisation setting bass to min and treble to max but the sliders seem to have little effect on the voice comprehension. This is puzzling as most people seem to say the Era 100 is better. Perhaps there are bad batches. I am not sure now whether to keep the One SL. The one benefit for me of the Era 100 is the volume slider but the sound is annoying me, particularly as I mostly listen to speech radio. Is this something Sonos support can fix, for instance a replacement Era 100. Do others receive muffled voices from the Era 100.