No Featured Images displayed

I am using this theme in my WordPress training courses and having an issue where the Featured Images for the posts displayed on the homepage are not showing up. I am running WAMP server and have WP5.1.1 on the localhost with Foodmania installed. Any suggestions? I do not have any plugins activated except Essential Content Types. Screenshot of homepage below: https://snag.gy/j2gGMu.jpg - homepage https://snag.gy/Q7bPqc.jpg - showing featured image has been set Anyone able to advise why this isn't working?