Automatic Mission Fail In Scortching Sands

[Batleth777]

I just bought Origins and have been playing through the missions on Heroic difficulty. But I am unable to finish "Scorching Sands" in the German campaign. I have no problems with the first part, but once the second part begins where you have to "hold your positions on the hill" there's the cutscene with the howitzers only the camera moves off the map and no howitzers are visible and then it abruptly says I failed the objective to hold the positions. The level then ends. I have tested this without even selecting a unit or issuing any commands and the same thing happens every time.

Also, unpon reloading the AT guns that are linked to the supply trucks disappear and my units are grouped together, even if I already created separate groups for them.