Just a follow-up to my post.
I've been communicating via e-mail with Gordon over at IQAudIO for advice. When I mentioned I was trying to play 24/192 FLACs he asked if I was trying to do so over wi-fi, which of course I was.
Now, after getting the UI updates and switching back to a cable at Gordon's suggestion 24/192 FLAC is DSP (dead solid perfect). No stutter, no drops, gapless is perfect.
Athough wi-fi would have been convenient I have no problem going to wire as I have wall jacks behind my stereo rack (foresight from 15 years ago when I finished my basement ).
For those trying higher bit rates, try a wire once and see what happens.