Hello there, thanks for taking the time to post a bug report! We'll need some logs and saves to be able to find out what error is causing the game to soft lock. If you press "Local Folder" in the game's Main Menu, this will open the directory for the game's logs and saves. If you open the "Logs" folder, there should be an output.log file, this is one file that we'll need. We'll also need your saves, so in the "Saves" folder, there should be a save for the mission when the soft lock happened. If you can send us the save and the output.log file, then we can figure out what's going on.
An alternative to this is to load the ground combat save, then try to trigger the soft lock. When this happens, press F11 and this will prompt the game to create a bug report .zip file for you. If you can send us the .zip file, we'd appreciate it too!