Change #1014699 had a related patch set uploaded (by Eileen; author: Eileen):

[wikimedia/fundraising/crm@master] Quick & dirty to make sure we don't upgrade paypal, amazon

https://gerrit.wikimedia.org/r/1014699

Just noting cstone & I looked into this & the message had gone into the fundraise up flow despite being paypal. We added a fix to prevent that in future but also realised that the new emails are going out to fundraise up amount increasers still & that seems wrong. We can address that but probably over the top of this chain of patches https://gerrit.wikimedia.org/r/c/wikimedia/fundraising/crm/+/1014669/1 since it needs a change to a class that doesn't exist yet

Change #1014699 merged by Eileen:

[wikimedia/fundraising/crm@master] Quick & dirty to make sure we don't upgrade paypal, amazon

https://gerrit.wikimedia.org/r/1014699

For posterity, the slack thread discussing this: https://wikimedia.slack.com/archives/C057U5C7HBQ/p1711511753989829

What happened, three edge cases combined:

There was an older fundraise up specific flow for if a donor changed their amount at frup and then we updated it to match in civi. And then with the recurring upgrade downgrade work we added in activities and emails to certain situations. The third piece was some very old paypal (not paypal_ec) donors have $0 for recurring amount in civi (looks like there are ~100 of these in total).

cid= 506030 had this situation where the donation came in as $10 and it went through updated recurring flow which actually fixed their recurring record in civi to show $10 and to the code looked like they upgraded from $0 to $10 which is why they got the upgrade email.

We added the patch above to keep only fundraise up donations going into that flow, which will stop this from happening in the future.

@Eileenmcnaughton made a separate patch to stop fundraise up upgrades from getting our emails https://gerrit.wikimedia.org/r/c/wikimedia/fundraising/crm/+/1014728 but this is not merged as @MSuijkerbuijk_WMF wants to confirm what the flow should be