Yup! Please read about the FCD issues and my rPi recommendations: FUNcube sample rate dropping and disconnecting - FIXED. The new software is highlighting problems that went unnoticed before (at least that’s what it’s looking like). You may have better luck if you spread the FCDs across the two hubs. But it may also be a different issue. I’ll take a look at the logs when I have a moment.
Update, looking at syslog:
Jun 16 00:01:53 localhost kernel: [4174395.837152] usb 1-1.1.4: reset full-speed USB device number 16 using xhci_hcd
Jun 16 00:01:53 localhost kernel: [4174396.010931] usb 1-1.1.4: 1:1: cannot get freq at ep 0x81
Jun 16 00:01:53 localhost kernel: [4174396.011196] usb 1-1.1.4: Not enough bandwidth for new device state.
Jun 16 00:01:53 localhost kernel: [4174396.011214] usb 1-1.1.4: Not enough bandwidth for altsetting 1
First line is reset of the FCD, second is a normal “error” message, third and fourth tell the story. I haven’t tried 4x FCDs on Pi4B, you may be able to get it to work by placing 2 on each hub if they actually are Multi-TT hubs. If they aren’t, each hub can only take one FCD, see that other thread I linked to.
All this is why I’m trying to make the RTL-SDRs work as well as the FCDs…