Hope your travels went well and thanks for the update here! Since Mconnect appears to also be struggling with the higher sample rates, this does indeed sound like a network-bandwidth issue.
If you want, I can check logs to confirm, you can use the previous instructions I noted above to send me a copy for review but at the end of the day this is appearing to be the limiting factor:
Well, yes and no. As I noted, Mconnect will play 24 bit at 96 Khz sampling with no problem at all. Roon won’t. even with the DSP setting to downsample to that resolution.
So yes, I realize I can’t play higher sampling rates but I’d at least like to be able to play at that resolution. I can do this with Mconnect but would rather do it in Roon.