Hi @st-h …
I was looking for easy first debugging steps, thinking along the lines of “If this happens a lot maybe it’s the volume of writes and there’s an inconsistency …”
But what you say … that there exists the possibility of a transaction interfering with another write … well, if you know that’s a possibility in your application, it certainly sounds like the first thing to look at.
Perhaps your code should handle exceptions and retry writes a few times in these instances.