Not wanting to crash this thread, just to notify you that I have also had this exact problem. Nothing fancy, not part of a repeater. Just some image upload options that were used in the header and the footer.
Worked everywhere (including CPTs) but not on archive/category pages of normal posts.
Disabled all plugins, still the same. Tried it with Image Objects and Image urls. On the archive pages it was returning the Image ID on archive/category rather than the url. In the end rather than try to work around it I just changed image upload to url instead which works fine.
I’m not sure this helps much but filing it anyway in case it might.
Thanks!
