Hello,
I've just noticed that in a standard report Campaigns with Opportunities also Products are included so that the Record Count is referred to Products instead of opps.
How is that possible? Has something changed?
I am unaware of any change like that, I do see that Products are available in a standard Campaigns with Opportunities report, but that's not a Report Type that I use often, so I don't recall off the top of my head if they've always been there.
To get the count of Opportunity Records, I would use Tom Tobin's "Power of One" technique =>
Tips & Tricks: "The Power of One" the Greatest Formula Ever Written*
https://trailhead.salesforce.com/trailblazer-community/feed/0D54S00000A7RsPSAV
Or use Opportunity_ID:UNIQUE
and filter the Report using Stage Change equals TRUE
Documentation
Count Unique Values in Report Results