Wd ex2 ultra disk 1 slowing down

It seems the disk 1 is kind of failing i guess. As it reduced copying/writting speed from 100+ mb down to 40-72Mbps

I tried the same file with disk 2 its copies above 93Mb/s till 110Mb/s

Initial setup was JBOD 2x 2tb wd red .

Now did a re-raid - vol-1 with 1.82tb and 298gb spanning.

As changing from JBOD to this took like 2hrs plus only for disk 1. As disk 2 done in less than 15 min.

But to my surprise the disk 1 stuck at 90% for almost 2 hrs and frequent timeout as well.

See the dedicated subforum for the EX2 series where people more familiar with that device may be able to assist. This subforum (My Cloud) is generally for the single bay My Cloud drive.