A week or two ago I realised that - seemingly after a recent SD update - my Airspace Wanings settings were all reset to OFF, with the exception of Parachute Dropzones (which was defaulted to ON although I as far as I remember I had this set to OFF). This is the place in Navigation Options where you select the airspace categories you want SD to alert you of. I observed this simultaneously on two iPads (iPad mini 5 and iPad Pro 2020). AFIK, the user settings here are NOT synchronised across devices.