Because your using an EX2 Ultra you may, if you haven’t already, want to see the dedicated EX2 series subforum where there may be past discussions relevant to your issue. One can find those past discussions using the forum search feature, magnifying glass icon upper right. There may also be people more familiar with the EX2 who may be able to assist. Generally this subforum (My Cloud) tends to focus on the single bay My Cloud units.
https://community.wd.com/c/network-attached-storage/wd-my-cloud-ex2
There is some discussion on copy speeds to the single bay My Cloud units in the following thread that may or may not be relevant.
