RTL after mission climbs after mission completes

,

I have my RTL home set to 100m, and my mission is also at 100m, however, once the last waypoint has been reached (46) my plane goes in in RTL and then climbs sharply to 160, before gliding back to 100m at home.

This happens after every flight.

I don’t have a RTL command at the end of the mission, so it’s executing the default behaviour. Is this normal? Why is this?

My parameter:

PARM, 384079634, ALT_HOLD_RTL, 10000

The instant in the log where RTL is engaged:

MSG, 2051087989, Reached waypoint #46 dist 20m
MODE, 2051088158, RTL, 11, 0
MODE, 2051088168, RTL, 11, 0
MSG, 2051088193, Mission complete, changing mode to RTL
BARO, 2051088328, 98.81022, 99858.28, 30.93, 0.835568, 2051088, 0

There is a high altitude error immediately after reaching the last waypoint and going into RTL:

Waypoints:
CRF110ha WPs.txt (3.7 KB)

Log:
https://1drv.ms/u/s!AuY_xJ25med9hJ9-pZsAKCRJ0FWCRQ

Can anyone explain this behaviour?