My 2019 MDX does this. The reminder says to use firm pressure on the brake pedal to activate auto-stop feature. Either way it is still annoying.Not sure how this plays out in all model years, but I've noticed that my 2020 MDX will allow me to control the auto-idle with the pressure on the brake pedal - light pressure but full control and a full stop does not turn off the engine. If I then fully depress the brake after a stop, it will turn off. Likewise, full stop and full brake pressure immediately turns off the engine, no reminder on dash. When I say immediately, I mean after about a second's delay. The MID in the dash always has this reminder each time I stop with lighter pedal pressure (but I noticed this reminder can be turned off in settings). I didn't bother to look this up in the manual, but I'm guessing it's in there....