Had this exact thing in 2021 and handled it badly, so I want to handle it better this time.
Same offer - a straight email submit - running for eleven weeks. My tracker and their dashboard agreed inside two conversions a day for the first seven weeks. Week eight they stop agreeing. My side says 411 for the week, their side says 362. Week nine, 398 against 344. It has not closed since.
I opened a ticket and the manager came back with the usual - duplicate filtering, advertiser-side scrubbing, some leads failed validation. All plausible. All unfalsifiable from where I sit.
What I want to know is what an actual manager will accept as evidence. Last time I sent him a spreadsheet and he sent me a paragraph and that was the end of it. What do you send that makes the conversation continue instead of stop?