RankMath Facebook Image Snippet Not Showing Up

We have recently updated the design for the website https://colsimphotography.com and we updated the Facebook snippet with RankMath.

However despite the correct image showing up in the meta data of the HTML of the main page. The Facebook Post Image still shows the old website.

Previously Facebook was showing the correct image but every few days it seems to switch back to the old image and we do not know why. We have tried setting the Post Image within the general settings and specifically in the page settings but it still does not fix the issue on Facebook.