High Sierra.
Ethernet, network is ok.
Actually no, but I do only have another Mac with the same OS in the house...
Yes, I think it should be the automatic one.
Especially when moving to the unRAID, but sometimes also the other way. Also, when I move files from folder to folder inside the unRAID, it also gets really slow. Should it be faster? Because the files are already there and if I move them from a folder to another one I'm not actually writing anything new to the disks...