That helps a lot. One issue I see, but unrelated to your problem, is that OSCAR is reporting that you are in fixed pressure CPAP mode on the A11, but the graphs clearly show it is in Auto APAP mode. Must be a bug in OSCAR. I still use Sleepyhead. I believe OSCAR is supposed to be compatible with A11, but it appears is is not fully...
What I see unusual in the A11 graph of the mask pressure is that there are times when the mask pressure drops very low, below the minimum pressure of 4 cm that it is supposed to always maintain. See the screenshot below where I have highlighted the areas. It may be worthwhile to expand out some of those areas and see what may be happening first. It's possible that it is a chicken and egg situation. Are the deep breaths causing the mask pressure drop, or is the mask pressure drop causing the deep breaths?? You might see that if the time scale is expanded out in one of these. The one at 1:37 seems to be the worst.
These machines are designed to always maintain a minimum of 4 cm of pressure. It is possible that this particular machine is defective and cannot respond quickly enough to dropping pressure. Depending on where you got the machine it may be hard to convince them of that possibility. They may respond to a screenshot clip showing in detail what is happening.
One other thought I had was that you may want to try setting the machine to a fixed CPAP pressure to see what happens. That may let the machine respond better to quick deep breaths. Not sure, but it is easy to try. I would suggest a fixed pressure of 8 cm based on your data that you posted. Then it may have to be fine tuned up or down to get an acceptable number of OA events. But, 8 cm should be close. This is a bit of a work around to the underlying issue though if the machine is defective and not responding quickly enough.
You don't seem to be using the Ramp feature. If you want to try it, I would suggest setting the Ramp Time to Auto, and the Ramp Start pressure to 7 cm if you want to go with a fixed CPAP mode of 8 cm. That should be comfortable to go to sleep. The Auto ramp feature hold the pressure at the ramp start pressure until it decides you are asleep and then ramps it up to the set pressure of 8.
Hope that helps some. I would be interested in seeing a screenshot of that event at 1:37. It may tell what is happening first.