Blurry Photos through API

When I upload photos in Canva to edit them than I use the API to go through Constant Contact for posting on Social Media like Facebook, Instagram, and LinkedIn they are showing blurry. It is not all the photos but enough for it to be a problem. They are all taken with the same professional camera all put in Canva and uploaded the same way through the API. I am confused on why this is happening and how to fix it.

Free September Webinar

Join us for this free, one-hour webinar to build a proven email marketing strategy that takes the guesswork out of creating email campaigns that deliver real results.