GPS fail safe not working

Hi,

I have the following setup:
HEXAcopter frame
Pixhawk flight controller
Firmware version: ArduCopter V3.2.1 (36b405fb)

After I flew an autonomous mission ended with landing i flew again in the loiter mode this time i lost the GPS signal (GPS HDOP climbs rapidly ) and the the GPS glitch was detected and the GPS fail safe was triggered (alt hold), but the hexacopter rolled and accelerated without control even from rc transmitter and dived into the sea , it seems that it flew according to the not correct GPS data . Can anyone help me .

I don’t have any log files for this mission because my hexa now under water :cry: and i was using my smart phone as ground station.

,

can anybody help?