No Metadata image of new files after re scan of library


When i add new files to my tv show folder and then do a re-scan of the library to add them to the list it adds them and the episode info but it doesn’t add the episode picture and instead uses the season picture.The only way to sort this is to go to each new episode and manually re-load metadata but i thought that by re-scanning the library it should bring in all the new episode pictures along with the info and not need me to manually do each one.

Any help re this will be greatly received

Thanks in advance