VTOL fails to speed up after transition?

Had a quick AUTO flight today with a Nimbus 1800 VTOL but it did something a little unexpected. After the 30m alt transition point, waypoint (#2) was at 60m but the aircraft had only reached 45m by that waypoint and it’s airspeed was only around 10m/s (36km/h), so too slow and very near the stall. Only nearing waypoint 4 once the altitude had reached 60m then suddenly the aircraft sped up to 18m/s (64km/h) before slowing to 13m/s (47km/h), it’s cruise speed.

So why so slow all the way to 60m? The aircraft has enough power to climb at easily 13m/s+ yet it flew so slowly to reach 60m?

I’m interested in this topic, my next flight will by AUTO mission.

I think my ARSPD_FBW_MIN is too high. The aircraft doesn’t quite reach ARSPD_FBW_MIN of 9m/s during transition so doesn’t complete the transtition. Will try lowering it on next flight.