Inhalation to Exhalation Ratio

I've seen several posts mentioning this subject.

Is there an explanation as to what it means when this ratio becomes inverted. I.e. the inhale time is significantly longer than the exhale time?

Probably that your IPAP pressure is lower than it should be and that the EPAP is higher. Or that you've grown a check valve in your nose... Did you change anything in the settings? I think I'd see that if my machine turned into constant PAP mode. I can't see how this could happen spontaneously, though.
McSleepy