@ewald - I have the same issue with CU 179
for me - External SSD connected via USB, EXT4 format, does not mount after reboot, cannot mount via EXTRAHD.
The only indicator of “odd” was the red circle on the right:
For me I deleted the devices in the /var/ipfire/extrahd/devices and then I was able to add a drive.
Still testing.
FYI - From what I can tell, the EXTRAHD does not populate /etc/fstab so I am not sure what happens on a reboot.