I made my first purchase with your company for a Resmed S11 plus accessories in Nov 2023. Your handling staff was very helpful and the delivery by FedEx was punctual. However, I have a major concern that there is something wrong with the S11's algorithm. The daily usage readings for the past weeks have ranged from 2.5 to 4 hrs when it should be around 7-8 hrs. I am afraid that I may not be getting the proper treatment with the machine. I have sent an e-mail to your staff with my usage readings a few days ago and awaiting a response regarding any need for the machine to be sent back for repair.