IMHO should be the problem in your shortcode.
Try this one: [iframe src="https://woobox.com/ovfytc"]
But wait, that ahortcode will not work too because page “https://woobox.com/ovfytc” is redirected to “https://www.facebook.com/FishingReviewsTV?sk=app_143103275748075&app_data=dlt-1”
So try this shortcode: [iframe src="https://www.facebook.com/FishingReviewsTV?sk=app_143103275748075&app_data=dlt-1"]
But that shortcode will not work too ??
Because facebook is blocking usage inside iframe with header x-frame-options:DENY.
It was not your lucky day ??
So choose some other page to embed but use such syntax: [iframe src="https://site.com/"]
