The SDR system is down due to a cable failure.
I tried to check on the SDR again today, and again it was down. So I went and did a full inspection of it. The result: the Ethernet cable is bad. It’s an outdoor-rated 50-foot cable, but something is wrong with it. I was able to get the SDR setup to work inside my shack with another cable.
So, until I get the cable replaced, the SDRs are both down.
Oh, and I made a video of my inspection. It also shows the SDR setup in detail, with me describing it: