Which operating system are you using Android or iOS? You are mentioning another post related to the issue that you are facing - could you send us the link?
At the moment we are investigating what could cause the issue you are facing.
If the connection between the Pix4D capture and the controller is broken, e.g. the app closed, than the drone will continue the mission since it is already loaded (the waypoints to be followed) but the camera will not trigger pictures anymore. In this case it is only possible to take manual control using the controller to interrupt the mission.
Did you have the chance to try the app in the meantime? Does the issue persist?
There is a new version of the iOS app - did you have the chance to install it and check if the issue persist also with the latest version?
You are mentioning that you use DJI GO. Check that the manufacturer’s app is not running in the background especially after connecting the device to the drone (force quit other apps).
Keep in mind that you can manually take over the drone by using the controller.
Could you please let us know if you are using the Android or iOS version of the app?