#6060 suninmyeyes.
Point of interest - you mention that you never select Stby. on the transponder, even when selecting a new squawk ?
"in my day" we were told to always select stby. when re-selecting, to guard against "accidentally" - even momentarily - pausing on one of the "77XX" emergency selections whilst re-arranging the numbers, to do so would immediately set off an alarm in the ATC unit monitoring, and even if immediately changed would raise suspicions that you were in trouble, and subsequently trying to mask the situation - i.e. a hijack attempt, so action would be irrevocably started.
What's changed ?
Thanks.