watchtv.cox.com always sets audio to Unmute when selecting a channel

When audio is muted on the watchtv.cox.com website and the channel is changed or even when the same channel is re-selected, audio is always restored to the audio level before audio was muted.  Mute is not retained when selecting a channel.  The website is automatically resetting audio to "Unmute" when a channel is selected.  This is either a coding error or a seriously arbitrary design choice.  Currently, the only way to maintain muted audio when changing channels is to mute your computer sound.  But, this defeats the purpose of the website's mute option: keyboard shortcut  "M "or repeatedly press the "down" arrow.