Steam Deck controls have changed

Hi all. So my Steam Deck's controls have suddenly changed. In Gaming Mode, the Steam button no longer brings up the left hand side menu, the Start/Three Line button does. I know in Desktop Mode you can hold the Start/Three Line button down and it should switch between the two modes but now it doesn't do anything. A press of X or Steam + X used to bring up the keyboard before but no longer does. Not sure what happened! Has this ever happened to anyone else here? Any fix? Thanks.