WDMYCLOUD Write Speed Suddenly Slow

I have the latest Firmware on my WDMYCLOUD. I have a wired connection to my gigabit router from the MYCLOUD. My router also has AC wifi that I connect to my MYCLOUD with through my WDTVLIVE and my laptops.

I used to be able to connect to my WDMYCLOUD via my laptop and transfer files @ 30MB/s for both read and write.
Suddenly yesterday I began only being able to get 4MB/s write speed. I still get 30MB/s read speed and writing FROM MYCLOUD to other devices, but I cannot write TO the WDMYCLOUD at any higher than 4MB/s.

Does anyone know what would cause this?

Have you tried rebooting your NAS or a system-only factory reset?

I did try to reboot and I updated the firmware to the latest version (I guess the same as a system-only reset) but had the same results. I think I figured out my issue though. It seems that when I hook into ethernet my speeds are normal again. They also seem to be normal when writing to the MYCLOUD from my smartphone via wifi. So I am convinced it is my laptop running Windows 10. I recently had a large cumulative update for Windows 10 and I am persuaded that is what is causing my slow speeds suddenly.