Flickr had been transitioning recurring subscription users from Digital River to Stripe for a while, but abruptly ended remaining Digital River subscriptions around November last year. It seems to me like this could likely have been why. There wasn't much transparency around why the abrupt change, but a few months of missing payments might provoke that...

Users that used PayPal through Digital River were pretty unhappy about not having the option to continue using PayPal for Flickr.