cast/crew images blank until clicking on them

[chenks]

i seem to have an issue with cast/crew images.
across all tv shows and movies it seems to scan and show about 70% of the images , with others left blank.

however, if i click on the blank ones it then displays the images , and going back to the cast/crew page it then displays the images that was previously showing blank.

is there a reason for this?

example before clicking on blank image


example after clicking on blank image