Always difficult to say whats the root cause if you do not know a setup.
How often do you get these audio glitches? Only when working in the DAW (with the ASIO driver) or also when listening to e.g. Youtube (when using the WDM driver). Did you notice, whether the audio glitches might be related to the CPU load? Or do they also happen on an IDLE system when perhaps only audio playback or Youtube is running (which usually has only a low CPU load).
I would start at the beginning, to describe the hardware and the setup.
Can you provide perhaps a little ASCII drawing? Where are the monitors connected to?
What kind of computer are you using (laptop, desktop, CPU, mainboard, GPU)? It would be interesting to know which components you are using.
So you have a UFX II and a UCX II? The devices are probably connected via ADAT in both directions. Then why did you set up word clock between the UFX II and UCX II?
This is am unnecessary additional cabling and I would leave it out. Not that you have issues the way you setup WC.
I would leave the UFX II as clock master (clock source = internal) and the UCX II could just as well receive the clock via ADAT. Then you can save yourself all the (probably superfluous) WC cabling.
It might help to try all USB ports, whether it makes a difference.
If you connect a lot of devices via USB it might help to connect only the required devices (mouse keyboard) for the troubleshooting. And to have more ports that you can try with your UFX II.
I wouldn't exclude that the problem might be related to your computer setup.
Did you perform the usual things like disabling energy saving in the BIOS and in Windows?
What energy profile do you use in Windows? If it is not something like High or Ultimate performance then it can be the case, that the DPC latencies are getting too high and that the computer is unable to process audio in time. If working with DAW and do audio processing with VSTs etc .. you should always use the energy profile which delivers you best performance.
You can google for the hidden power profile Ultimate Performance. With one command you can enable and use this (it might be required to re-loging or to reboot until it is visible).
I would also do measurements with LatencyMon to check whether you have maybe too high DPC latencies, maybe caused by bad drivers. Wireless communication could also be an issue. I would test whether DPC latencies are lower or whether it makes a difference if you work without wireless.
If you run Windows 11, do you have the kern isolation enabled. I mean, all those security features in Windows 11 which cost a lot of precious CPU performance? Then I would have the suspicion that the issue can also be come from this side.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14