nsa325v2 USB-HDD won't work after upragding internal HDDs

Hello community,

I own a NSA325v2 for about 4 years now. One of my internal HDDs failed, so I decided to do an upgrade from 2TB to 4TB RAID 1. I made a backup of my files with the front USB Port. Upgrade worked fine. Now I wanted to copy the files back, using the same USB Port. But none of the 3 USB Ports recognize my USB HDD. In the log files it says "An external USB HUB device is plugged."
But it doesn't show my USB HDD as an external Volume. I was using a 2nd USB HDD drive before my upgrade for backups. Same problem here. It shows up in the log files as an USB HUB device but won't show as external Volume, like it used to be.

Am I missing something? 

Thanks for your help!


#NAS_Nov_2019