[first launch] umbrel + X829 board ==> multiple external drives found

[dodikk]

Dear umbrel devs. I used a SATA board to conenct my SSD (see the link below).
https://wiki.geekworm.com/X829

After I've followed the "getting started" instructions from umbrel site, I got the error below

Umbrel only works with one external drive of atleast 1TB size. Please disconnect any additional external drives and restart your Umbrel.

I have only plugged in a single 2TB SSD to my raspberry pi 4B (8GB)

So the questions are

1. Could the error be caused by the board having slots for two disks?
2. If so, which SATA boards are compatible with umbrel?

Thanks in advance.