I am using Yoast’s video seo plugin, and it offers the ability to look for video content in custom fields. If you take a look at the screenshot, you can see I am using the field key for this…is equivalent to the WP field key?
For each custom field value saved on a post (video), ACF will save 2 records:
1. The value: This postmeta entry will use the field_name (video) and the value will be the field’s value (video url)
2. The reference field: This postmeta entry will use the field_name with a prefix (_video) and the value iwll be the field’s key (field_12353)
I think you should change your Yoast’s value to ‘video’, or what ever the field name is.