Thank you for your interest in the Intel Aero drone.
Your request has been received and is currently being investigated.
We will get back to you as soon as possible.
Thank you for your patience.
Take a look at this sample as it might be helpful for you: https://github.com/intel-aero/sample-apps/blob/master/ros/src/aero_offboard_ctrl/src/aero_offboard_ctrl_node.cpp
Also, offboard(manual mode) is supposed to work without GPS lock.
As for the script, I would need to see what script are you using to arm the motors, if you're using our sample scripts from https://github.com/intel-aero/meta-intel-aero/wiki/04-Autonomous-drone-programming-in-Python those are written to only arm the motors for 5 seconds.
You can also take a look at this thread: https://communities.intel.com/thread/115384
They seem to have an issue similar to yours.
Hope this helps.