I just got more information on this behaviour.
Below 50cm, the drone should get ready for a safe landing. As a side-effect, when the drone height estimation is equal or below 50cm, the drone delays the throttle down commands. It should not delay the throttle up or horizontal commands.
I am not sure what would happen to horizontal commands if they’re mixed with a down command but I imagine that they would be delayed too. Does this correspond to the observed behaviour of your drone?
Thanks, fly safe!