Facebook, Twitter, Instagram and Website are custom fields, and each custom field only appears in the places you pick for it. If the links show on your archive pages but not on the listing’s own page, the fields aren’t set to show there.

Choose where a field shows

1. Go to Places > Settings > Custom Fields.
2. Open the field, for example Facebook.
3. In Show in extra output location, add Details page sidebar. Add Listings page as well if you want it on archive cards, or Map bubble for the map popup.
4. Save, then repeat for the other fields.

Fields set to Details page sidebar are shown by the GD > Output Location element with its location set to the details page. If your listing sidebar doesn’t have it, add the block or widget, or this shortcode:

[gd_output_location location="detail"]

Place one field exactly where you want it

The GD > Post Meta element shows a single field anywhere on the listing page or its sidebar. Use the field key, for example:

[gd_post_meta key="facebook"]
[gd_post_meta key="website"]

You can also add fields to a tab on the listing page at Places > Settings > Tabs.

More detail: GD > Output Location and GD > Post Meta.