Some images not displaying on Safari
I am running an iMac with Catalina 10.15.7 and Safari 15.6.1 and some images from at least one particular website refuse to display, instead I get the blue ? box. The exact same website displays perfectly via Google Chrome and also on a MacBook/Air running the latest Ventura and Safari. Can't update the iMac since it is Late 2013 so cannot run Ventura and I am not ready to upgrade to a new iMac just yet.
I have generally found Safari to be a bit odd in the past, in that quite often websites do not run properly, whilst working perfectly on Chrome. I presume I have a duff setting somewhere, but have been through all the obvious things in the developer menu as well as clearing History and Cache, all to no avail.
Any suggestions gratefully received.
iMac 21.5″, macOS 10.15