You’re most welcome.
For a situation like this we would not need to mail anything back and forth. We would simply mail you a pre-updated dock as I had mentioned earlier and once it arrives you can discontinue use of the original dock. Typically sending a replacement only takes a matter of days, I wouldn’t expect this to be a multi-week process.
Otherwise, if you are able to gain access to a Windows host to perform the firmware update, I can send you the full instructions for how to do so. (The linked thread is out of date.)
Finally, that’s fantastic news to her moving the HDMI to a different input on the monitors have allowed full 4K @ 60Hz operation.
Best wishes,
Josh