Hey username201701,
This is possible. Please go to your WordPress Dashboard – Facebook Feed – Customize – Style Posts (sub-tabbed page) – scroll down to the setting “Maximum Post Text Length” and remove the number in the box next to it. Then click on “Save Changes” at the bottom of the page.
The number represents the number of characters to be displayed before truncating takes place. Removing it means that no truncation will take place and all text in the posts will initially visible.
If you have additional questions please let me know as I am happy to answer them for you. In the meantime I hope your week is going great.
