My thumbnail does not appear when shared via Facebook even though I have it uploaded in My Stories (size = 286 x 190px). I've checked the Facebook Developer Debug tool as well (https://developers.facebook.com/tools/debug/og/object/ ) and although there are some warning (see below and attached), I see the thumbnail appearing and referenced correctly (I think).
The story map URL is here: http://wa-water-trust.maps.arcgis.com/apps/MapSeries/index.html?appid=515bbd9d8e104d63ad12916ba3b29a7c
Any thoughts? Thanks!