For many years I've connected all I/O channels of my Pacarana digitally to the Apogee Symphony (AD/DA-16x) interface connected to my computer via a t.c. electronics digitalkonnekt x32 interface. Up until recently I was able to select the "AES | SPDIF | TOS 1+2" input of the x32 as an external clock source for the Pacarana.
For some unknown reason this no longer appears to work. Selecting any of the external clock sources flashes "OUT OF REALTIME" in the DSP Status window then about 3-4 seconds later it reverts to "Internal" Clock Source.
The connections are:
computer => thunderbolt => AD/DA-16x => AES/EBU => digital konnekt x32 => firewire 400 => Pacarana
I'm not sure precisely when this stopped working but I noticed it after upgrading to Kyma 7.30f5. Other than Kyma version and Pacarana firmware upgrades the macOS version, Apogee driver version, and cabling has not changed in the past year or so.