WH-1000XM3 spontaneously changes mode

[merseyswine]

My WH-1000XM3 headphones change mode (cycling between ambient off - ambient on - Noise Cancelling every few seconds without me touching any buttons. Could it be a fault with the mode-control button? 

[HannahEd01]

Hi merseyswine, try resetting:  https://helpguide.sony.net/mdr/wh1000xm3/v1/en/contents/TP0001703078.html

Also make sure that the headphones are clean.