DO NOT right click on the image and ‘save as’. If you do you’ll download the low res version.
Instead, go into the Club Content planner post for the particular day hover over the image and click on the black download arrow icon that appears top-right on the graphic itself.
Click any gallery image to open a larger version in a lightbox and the download appears top right of the screen (in the black bar above the graphic) NOT on the graphic itself.
If you’re posting on the move on your phone then you need to scroll to the image you would like to download and tap it to open a larger version in a lightbox. The download button appears in the top-right next to the close button (NOT on the graphic itself).
Following these instructions will force the high resolution image to download to your device. After which you can upload to your chosen social platform.