Thank you for your inquiry. The built-in social sharing features we provide will only post your sent email campaigns to personal pages and Facebook business pages. There is no direct way to post to Facebook Groups.
However, we do provide short URLs that will display your sent email as a webpage. This short URL can be posted manually to a group page on Facebook. Click here to see where you can find the short URL.
I am sorry to hear that you are experiencing this issue.
We have heard other reports of this happening when posting to that social media site. In this case I would suggest posting the share url of your email rather than using the social sharing feature. This is just a temporary solution while we work to fix this issue. Click Here for more information on the share url.
Again, I do apologize for the inconvenience. Have a great rest of your day!