NFZ Issues with COA and Unlock

This post is for DroneLink staff.  Other users are welcome to contribute similar issues, but due to client confidentiality issues I'm unable to publicly post images that show the location.  Please do not ask.

I encountered an issue yesterday while flying.  Drone stopped in mid mission and threw an error "Unable to Assume Control."  I was able to force close the DroneLink app and open the DJI Go4 and continue beyond and around the stop point.  I brought the drone home, landed, rebooted the iPad, went back, same issue.  Drone refuses to proceed beyond a point in the mission on DroneLink.  Brought the drone back, copied the mission, modified it to the affected area and re started, same issue at the same location.  Verified that there are no obstacles in the area with DJI Go 4, manually flew the image capture in that area.

I have flown this site previously with Pix4D twice using similar mission profiles.

About the site.  The site airspace is charming to put it nicely.  There are two LAANC grids present (150 and 50) and a NFZ on the North end of the site due to a runway approach.  Flight was taking place with an FAA COA, ATC verbal authorization, and a DJI Unlock.

This snafu ran me out of daylight which unfortunately is a giant hassle.  The COA expired yesterday, so now the client has to go back and extend the COA (it's their COA) and then we have to wait for the weather to be just right and ATC to be willing to restrict one of their runways at KIAH.  

In dissecting the situation afterwards the DJI Unlock was larger than the needed area, so that rules it out as the problem.  When you are flying on a custom unlock the drone will stop at the edge of the unlock and not proceed.

I was below the max AGL for the COA and Unlock so that rules that out.

I could fly manually in DJIGo4 and had already flown in this area manually as part of this mission.

The incident happened right where DJI's NFZ is drawn.  I really hate DJI imposed NFZ's.  What's odd is that I had crossed that NFZ boundary several times during this mission in automated flight.  However, the problem is happening right at the approach apron boundary, so that makes it a prime suspect.

Are there any known issues with DL that could be causing this?

I will be going back to this location again and would be happy to gather some data if there is something specific that would help determine what is going on.  I will probably have to fly this in Pix4D next time as I need to just get it done and move on.

I'm also happy to send some images to DL support directly.  I just am unable to post them due to NDA's with the client.