The Secret Bose QC35 Series II Hardware Update - YouTube
Bose QC35 owners accuse recent updates of destroying noise cancelling
Downgrade your Bose QuietComfort 35 II from any version to 4.3.6, 4.1.3, 3.1.8, 3.1.7, 2.5.1, 2.2.1, 2.2.0, 2.1.3 or 2.0.1 : r/bose
My new Bose Qc 35 II. I have tested both this and sony XM4 and gone with Qc35II.So much happy specially with 4.8.1 firmware. I wonder it is competing with 2020 XM4
Updating the software or firmware of your product - Bose on-ear wireless headphones
Bose fends off claims 'noise cancellation-breaking' firmware update was intended for sly sales boost | ZDNet
Bose QuietComfort 35 II Noise Cancelling Bluetooth Headphones— Wireless, Over Ear Headphones with Built in Microphone and Alexa Voice Control, Silver : Electronics