On occasion a Legacy tour may not show correctly on Facebook, often this happens when an update has been made to the tour (like the address, main picture or title). To ensure the tour shows correctly when posting to Facebook, the link needs to be debugged through Facebook. Think of it as clearing the cache / history for your Facebook account!
1) Go to this website: https://developers.facebook.com/tools/debug/
2) Enter your listing website link
3) Click Fetch New Scrape Information
4) Scroll down to the bottom of the page to the section "When Shared This is what will be Included"
This will show you what your post will now look like on Facebook. You may have to click on "Fetch New Scrape Information" a few times until you see the changes you want.
Once information is how you want it to appear, you can close the page and then post the link to your Facebook page like normal!