iOS Web App Inexplicable Opens YouTube App

For the life of me, I can't figure out why my website's web app suddenly started automatically opening the YouTube app. Originally, I had a YouTube widget, which I removed thinking it might be the culprit, but no luck. Could anyone with more knowledge please shed some light on this?

Steps to re-create:

1. Add mtscollective.com to Home Screen via Safari
2. Load web app
3. "This video is unavailable" loads

Thanks in advance.