Glad you got it working. Don't want to come across as rude but the most likely cause is not hardware but user error. Those groups of 4 spade terminals on the PSU are all connected to exactly the same point so the order you plug them in won't matter.
It's significantly more likely that just unplugging and replugging things has meant that something that wasn't connected properly before now is connected.
There is a chance his top ground spade terminal has a poor connection- a cold solder joint or something, and moving to terminal 2 provides a better connection.
Personally, now you know you can get it working I would try switching your ground spade terminal 2 back to terminal 1 and see if the fault is still there. If it is you should get it repaired. It would be a 30 second job with a soldering iron reheating the pads on that spade terminal. If it was my PSU I would do it myself but you may prefer to send it back. But honestly I expect you will find it works just fine
hi,
many thanks for the explanation. it seems weird to me that both PSU's were as they came from the factory (unmodified), but still you had a grounding issue when connecting modules from these two cases.
best regards,
Bakis.