It does happen; you have to adjust the mask to reset the seal.

I have been on a CPAP for a month and had the same issue. The sleep lab had me adjust straps and position lower on my nose. It worked. They say to explore and adjust until it's a good tight fit. Hope that helps.

I use a bipap and a full face mask. I always had the problem of air leaking out around it. My therapist gave me a very thin liner called a RemZzz and a smaller mask and that seemed to do the trick. You can get the RemZzz's at most hospital supplies and also on Amazon. The down side of this is insurance doesn't pay for them and they aren't cheap because you use a new one every day so I started making my own out of thin baby receiving blankets. Any kind of thin material works. I cut them out and can use one for a few days. I don't know if there is one for a nose mask but it is worth checking into. I get a much better nights sleep since padding the cushion with these. Hope you find an solution to your problem, this can be very annoying. Hugs!

I have never used a C-Pap, but my son does due to sleep apnea. He has to go into the store every so often with the mask to have it adjusted, or replaced. It sounds like yours needs to be adjusted, or you may need a new one.

I had to play around with the different sizes of nose pillows. S,m, or large. Sometimes if you have the mask to tight it will leak. Depending on what style of headgear you have you just have to find what works best. When you get it right it shouldn't leak.