Having real problems with the header image sizing. I have always used 16:9 but this is not working now. Looks fine in the editor, fine on mobile but on the blog page it has cut heads off and on the Facebook share. I keep cropping it but its not changing.
What is the optimum size for all platforms please?

Editor

Blog feed

Hi Sandra,
For cover images to appear on your Blog feed (one column layout) without cropping it is recommended to use ratio 21:9.
For sharing on FB the recommended image ratio is 1200 x 628 px. In the future we are planning to support the relevant images ratio when sharing on social platforms.