Because all 4 vehicles have the problem,it makes me think that the issue is a protocol mismatch between the car and the dc charger. Or the adapter.
I believe your 4 vehicles were made for the US market. The DC protocols were probably only those applicable to the US. In Egypt, you probably have European-Middle Eastern protocols at your DC chargers.
Since ABB makes DC chargers for the US, they might have legacy US protocols still used anywhere there is an ABB DC charger, as they developed the protocols, and see no reason to bother to remove them.
EVBox, while having offices in Illnois, Los Angles, and San Francisco, I have never heard of them or seen their chargers publicly in the San Francisco Bay Area. They are headquartered in Amsterdam.This makes me think that their chargers are European - Middle Eastern centric. At least in those parts of the world. So there is no protocol to communicate with US cars.
Alternatively, the protocols might be extremely similar, but just a slight timing/voltage difference.
If you had the problem with only one of the cars, I would have suggested that you check a certain HV connector near the 12V battery. As that one has a reputation of being improperly connected.
I cannot remember, but maybe a few FFE were sold in England. If you could get the firmware for the onboard DC charger for those vehicles, and put it into your US vehicles, it might work. Or, you were to pull the DC charging equipment from those England vehicles to retrofit into your US vehicles.
It sucks that there is not a world wide charging standard, as you would think they would have one by now.
Reminiscent of the Beta/VHS wars.