The tranid needs to be unique. The process that updates the tranid I imagine is not happening between 2 requests resulting in one being created as "N/A" and the next one being rejected. Consider using a unique value such as time since epoc (I know, you could have the same request at the same millisecond but you can always search for a tran with the same id if you really need to lock it down)

I could definitely set a unique id such as what you’re suggesting, but the thing is the tranid doesn’t need to be unique due to how I set it up, so 999 out of 1000 requests do get n/a as their tranid, and it stays that way for up to a few hours. But for a very tiny number of them, it just doesn’t work for some (to me) unknown reason

It will be fine for a few hours so long as a second transaction isn't created in the mean time. Only one can have that TranID at the same time.

But a bunch of transactions are created almost simultaneously (an integration that sends multiple requests per minute), and a user event script that sets the tranid to “n/a” on before submit. This is a search I just ran, displaying multiple transactions with the same tranid. Or am I misunderstanding what you’re saying? It just doesn’t make sense that almost all of the requests are created like this, the way they should, but then suddenly it just doesn’t work for one. It keeps working for the next one after that too