Hey Dave,
Friday night (12/6/2026) we've encountered the first occurance of this happening ever and now every time subsequent. I have written a similar piece of software for ourselves and I have checks in our system which reported a heap of duplicates (245 records in Sale/Invoice/ spanning roughly 20 months) 3 duplicates in one month, 20 in another and so forth. I've checked if its my fault but it looks like the api is straight up reporting the same line (same SaleUID) a couple of times here and there.
I am fixing the data after a sync by checking for duplicate SaleUID ids and deleting one of them before using the data.
It feels also at the same time this started that I'm getting very few cache hits with the etags. Looks like a lot of the data is dirty every sync making every sync much slower than before Friday.
Not sure if this is exactly what you're getting but its in the ballpark for sure!
Hope they sort the issue for us and good luck to you sorting your duplicates!
