I Use A Cpap Machine With An Attached Humidifier. I

i use a cpap machine with an attached humidifier. i have developed a very bad cough and bring up phlegm all day. i purchased the new sanitizing machine called soclean. it does a great job cleaning the mask and hose but the phlegm problem persists. do you believe that there is a corolation between the cpap and the cough? i have had this every since i decided to turn the humidifier up to the maximum setting because i had a dry nose