Okay, lots more testing done. I believe I've narrowed this down to the issue:
MC22 for Linux (both ARM64 and AMD64) have problems opening various DSD files over the network when connected to a library on a different computer - almost as if it can't grab the file.
What has me onto this is that I took 9 DSD albums (3 ISO, 3 with individual DSF files, and 3 with individual DFF files) and put them on a hard drive that I connected to the Pi by USB. I've tested constantly over several hours and never had a failure.
I don't believe the network itself is the problem because when I used the iMac/Debian machine, and could finally get a file to play, I could monitor the network traffic in and out of the machine and there was no issue with the file download for each song to play. It would show it was receiving the file at about 10MegaBytes (not bits) per second, which is plenty fast. Additionally, if it were a network problem, when I played it on the Mac, if networking was the problem then I should have seen it there. Also, since 24/192 files play fine, that also seems to show that network speed/latency is not the issue.
So, since the iFi DAC works with MC for Mac, using a remote library over the network, and since the DAC works on the Pi with a local library that leaves only the combination of the Pi working with a remote library as the culprit - and since it will work from time to time with no network issues, it seems to point to MC22 on Linux.
I'm open to any other thoughts, but at this point, it seems like it's a bug with MC22 for Linux.