Given that no problems show up in 2.3.27, and looking at the diffs between 2.3.27 and 2.3.32, the only substantive difference is in syncprov_checkpoint handling, due to ITS#4720. Looking over that patch, it's possible the chosen fix was bad.
Try turning off syncprov-checkpoint in your provider. If that makes a difference, then the ITS#4720 patch is broken.
So far, that hasn't made a difference. The two problem consumers still do the same thing. These particular consumers are in a different network, and are heavily firewalled. I brought up a test consumer on the same network as the provider, and it stays in sync 100%. So, I'll need to poke the network to see what I can find.
Thank you both for the help so far.
Wes