Looks like Fruitbat is using some other site to host the image files... https://u.cubeupload.com/
No idea why they do show up so later for you, maybe your ISP limits traffic from/to that one? I dunno ...
Edit: Are you on BT? Found this:
https://community.bt.com/t5/Home-setup-Wi-Fi-network/cubeupload-images-not-appearing/td-p/1998113