!! ADMIN POST !!
seems like we haven't had images load for a bit over a week; apologies for taking so long to address this. the cause was that the SSL cert for the object storage domain (files schelling.pt) had expired, as I had forgotten to renew it at the same time as the primary cert for the root domain. I've resolved the issue & will try to find time to automate the cert renewal so that we don't face this issue again
a Schelling point for those who seek one