One loopback channel is marked as failing, but it is on the edge.
Do you run your test with RF cables connected?
I bought it a week ago. I did not understand it. Yesterday I decided to make out, of course, the quality of the connectors and their physical connections to the aisle, which is surprising for such a receiver. I advise you to reconsider something for the future. Two antenna wiring immediately fell off. I tried to connect them again and test. This time everything is fine. In future versions of the receiver, I advise you to reconsider this problem. Not only are the antenna wires there long and just lie across the board, they are also connected to the pins with play.
As far as I understand, you are talking about LimeSDR-USB in aluminum casing. Am I right?