Hi @superlisa,
Glad you like the plugin, seems like your overlay uses a z-index of 100001 so we could change the twitch plugin to use 100000 and it would be behind your overlay. We have made this change in v1.3.2 which should be forthcoming. Let me know how that works for you, we would love further feedback.
For now, deactivating deleting Yoast and then installing the old version has fixed the issue until the fix comes through as an update. https://downloads.wordpress.org/plugin/wordpress-seo.14.0.4.zip
