Revving rpm issue when braking

Hi,
I have 2015 CX-5 and about a month ago had an issue when breaking or neutral gear RPM went up at every stop and when break was released it shakes and moves forward with all force. When RPM went up there was a sound as if I am pressing a gas pedal which I was not. I took it to mechanic and he reset the computer and the issue went away. First when I took it to autozone the issue appeared something to do with air filter but after the reset it was all good.
A month later the same issue is occurring and I took it back to the mechanic and his computer is not showing any issues so we are not sure what to fix.
Anyone had similar issues? Mazda dealerships don’t have any appointments for several days and I am scared to drive it thanks![/QUOTE]