As a result the selected OG image is too small and is overridden by the image from the social share plugin as that is next in the image order hierarchy.
The issue of social share plugin's default image overriding other images is not new however.
The default parameter is set as 200x200 px; which satisfies Facebook's OG image criteria, hence the social share image is always used if available. This image needs to only be there as a backup in case the page or content does not have any better images