Device air leak, not mask!!!

[xaid]

When I exhale I feel air coming from the left side of my dreamstation (the side where the SD card and the filter). Is that normal or I need to go for maintenance?

[Dormeo]

Check to make sure that the water chamber is properly seated and that the hose connection is tight. If you don't find a problem in either of those places, I think there might well be something wrong with the machine, though I don't have the expertise to be sure.

I see from your therapy thread that you were thinking of getting a ResMed machine. Maybe now is a good time to do that. I recommend a ResMed Airsense 10 Autoset, which is a tried and true machine. (Be sure you get an "Autoset" rather than other machines in the Airsense 10 line.)

If you can easily afford a more costly machine, you might consider the ResMed Aircurve 10 VAuto, which can do everything the Airsense machine can do, plus provide a wider pressure differential between exhalation and inhalation, which can help with flow limitation. (I notice that flow limitation was perhaps an issue for you earlier.)