Re: Bose QC 35 ii firmware 4.5.2
I've had the same issue with ANC for a long time, updated firmware many times without solving the issue. Little or no difference between low and high anc, a lot of white noise and lack of cabin pressure feeling. Tried the first downgrade solution on reddit with no better result. Then got the downgrade that made all previous versions available. Downgraded to version 2.x.x (cant remember exactly the version).
Did the "reset" function and then upgraded to 4.5.2. The first thing I noticed was that the beep sound when turning on the headset was different and the voice that told how much battery was left was gone. The button on the headset did no longer toggle the anc from off to high any more. Installed the app on iphone and set the function and then deleted app. Now the headset has both the cabin pressure feeling and full anc level, as they had as new. Also the difference between low, medium and high are as they should be. AE version of the headset.