I loaded up some cloud credit and launched a node from the panel in blender. It appeared in the node list, I gave it full weight (wanted to see how it handled my scene that would take 16 hours to render on 3 laptops networked, to estimate and stuff).
After some fiddling, it showed ready then synced. I started a still render to start, render failed. I checked the log, it showed several sync failures (node still shows synced in the panel) I repeated this a dozen times, testing render animation as well.
I used suggestions from the forum such as saving and reloading, repeatedly. I burned some compute credits in idle time trying to figure it out and gave up and shut the node down for now.
The behavior seems to be that it shows as synced until a render job comes, then it rapidly fails to sync. I didn't realize I could save the log to disk until it had removed itself from the node list and I was testing with a few local nodes to make sure it was working at all, but it reported no specific error other than failing to sync and render failed. Blender v2.81a Crowd Render v0.2.2