While landing the quad gives a throttle spike

I have a weird behavior in landing, in the return sequence, actuator control 0 (thrust) give a spike.
i have set the following parameters to a lower altitude cuz I wanted to check what’s happening

RTL_DESCEND_ALT 12
RTL_RETURN_ALT 12

log can be found here.

https://review.px4.io/plot_app?log=f68ef413-a889-4a83-9ec9-dfbc42d5fdaa