Stripe pays out daily, so there were about 900 I had to go through. Unfortunately, there is no way to export all the transactions to track down the culprits, so I had to go from page to page, copying/pasting 50 results and then deleting all of the matching ones to hunt them down.
Although that kept me awake very late last night, I did eventually find them. In a nutshell, there were about 5 transactions which had been tagged incorrectly and another 8 payouts from Stripe that never made it to the bank account (which I am now taking up with Stripe).
Now for some really good news: Whilst doing the above, I discovered that, when Stripe does a payout, it gives 2 separate dates: Created and Arrival. I’m not sure if they initiate the payout transfer on the created date and then estimate it to arrive on the arrival date, but from my sample size, the arrival date is very accurate.
With that in mind, we’re tweaking the Stripe statement app to work with arrival dates (rather than create dates) in hope that we can map transfers directly without using the transit accounts.