cid=983212 donated on Oct 17 related to a fundraising event using Stripe, STRIPE CH_1FUYMAIWQMMG1DALBUSRSWYU
Though it's not listed in Civi's Mailing Events tab, the donor then received a enUSC1920_E1 fundraising email on October 22.
I'm not sure how the Stripe contribs reach Civi, but @jkim_wikimedia confirmed that "They get automatic thank yous via Give Lively (ticketing platform) not from Stripe. It's sent immediately after their transaction." so it looks like Civi does not send the TY email.
I'm not sure what Civi (or IBM?) field the filtering scan for recent donors uses, but if there's a way to add Stripe donors to the filtering scans that would help us retain the donor goodwill generated by these events. Probably won't see a huge number of these complaints, but they are more likely to include MG contacts.