Hi Mark,
There’s custom CSS possibly being added by a third party plugin causing the issue.
See: https://share.getcloudapp.com/X6uE0q9q
Try #1 here to find out which: https://docs.generatepress.com/article/debugging-tips/
It would be best to find out which plugin is causing this and then reach out to their support for assistance with regards to this issue.
Otherwise, you would need a custom CSS like this to fix the issue:
ul.wp-block-social-links > .wp-block-social-link {
margin-bottom: 0;
}
Here is an article with regards to adding CSS: https://docs.generatepress.com/article/adding-css/#additional-css
Adding it through additional CSS should work.
However, as mentioned, it would be best to find out which plugin is causing this first and resolve it through there.
Hope this clarifies.