A couple of things might happen to a link on Facebook that would cause it to lead to a 403 or 404 error page. This is what they are and what you can do about them:
- Link previews on Facebook are based on Facebook crawling (basically scanning) the linked sites, and they changed their crawler in 2019-2020. This change could lead to some sites being displayed incorrectly.
- To fix such link previews, submit your Bitly link to Facebook’s link crawler to request that they crawl or scan the page again.
- Check that there are normal spaces on either side of the URL when you include it in the text of your post. You want to make sure that the URL is separated with spaces from other characters, strange "white" spaces, or emojis.