In May 2020 it was announced that American Express was limiting consumers to 4 credit cards, previously the limit was 5 (in February 2021 the Green card was considered a credit card as well). That limit has been relaxed again to 5 credit cards, this will need manual approval until Monday when the system will update.
I suspect given the timing this might have been pandemic related in regards to reducing risk, although limiting credit limits would have made more sense if that was the case. Still great news to see this being relaxed. You can see the limit for other card issuers by clicking here.
Hat tip to Walter Credit Cards