2021, CX-30 Grand Touring FWD Dark Gray
Mine does that too---after a little while when I am inside the car--even though I have the key with me...And I agree with you, if we have the key--this warning shouldn't be blinking. Common sense.No one have answered the question I posted earlier. The security light is blinking even when the car is standing unlocked in the garage. Per manual it should be blinking only when the car is locked and it indicates that the security system is active. To me it makes no sense at all -- there is no need to have security system running when the car is unlocked. I think this blinking is an indirect indication of the software bug(s) with the car failing to go to sleep mode and this in turn would explain the problem mentioned by OP and I have this exact issue too. The warning indicates clearly that the car did not go to sleep and the battery is discharging. I think the other TSBs may be of a similar nature but not the same problem that I have.
Would anyone care to post whether they have the same issue in their 2021 CX-30 -- the security light is blinking when the car is unlocked and the engine is not running?