Why does my AC keep blowing cold air between heating cycles?

One other thing worth checking is the airflow direction during standby. If the vanes park open and flat after the compressor stops, you get that annoying drift of air all night. Angling them down or using a quieter fan speed setting before bed made a real difference for me. And don't rush to replace the units over this. It's a known quirk of where the sensor lives, not a fault, and once you've tuned the setpoint and airflow it's mostly livable.

I had a similar head scratcher with ours, ended up sticking a cheap thermometer from the kitchen on the wall next to the bed to see what the room was actually doing down at sleeping height. Turns out the difference between the floor and the ceiling in that room is a couple of degrees, which explains a lot. Someone told me some units can take the temperature reading from the handheld remote instead of the unit on the wall, is that a real thing or am I mixing it up? beacuse if mine can do that I'd just leave the remote on the bedside table and let it measure where I actually sleep.

The point about the remote doubling as the sensor is spot on, I found the same thing. Our unit has a setting that reads the room temp from the remote instead of the unit itself, so I leave the remote on the bedside table and it tracks where we actualy sleep. Difference was night and day, the fan now stays off until the room really drops. Only catch is you have to remember to change the batteries, because when it went flat ours fell back to reading up high and the draft came back.

Before you settle for the workaround, have a look at how dusty the intake is. I give our bedroom head a proper clean once a year and there's always a grey fuzz built up around the sensor area, and a dusty thermistor can read high. Mine was over-reading by close to 2 degrees until I pulled the filters and gave the grille a soft brush and a low vacuum. Also check nothing sits right above the unit, a curtain or the top of a wardrobe traps the warmest air in the room and the sensor never sees the temperature down where you sleep.

Not sold on the vane angle tip. Angling the louvre down might move the draft off your face but it doesn't stop the fan pushing air around, and in heating mode the vanes should already be pointing down anyway, that's the default. What bugs me more is calling this a known quirk and leaving it there. If the app says 22 and the room is 19, that's a three degree gap. My bedroom head used to over-read like that and it turned out the sensor was just faulty, swapped under warranty and the fan cycling problem vanished. Same installer, one unit fine, one not, sounds like a dud part to me rather than physics.

Update: sorted. Tried the remote sensor trick someone mentioned here, dug thru the settings and sure enough there was an option to read temp from the remote instead of the unit. Left it on the bedside table and now it holds heat properly till morning, fan actually stops too. Also gave the filters a clean while I was at it. Sleeping much better.