1-) GO youtube.com and check with xprop _SURF_URI(STRING) = "https://www.youtube.com/"
2-) click on any video and check xprop _SURF_URI(STRING) = "https://www.youtube.com/"
3-) Use mod+r to refresh page and check xprop _SURF_URI(STRING) = "https://www.youtube.com/watch........"
Basically it doesn't update _SURF_URI when you click on video or any link unless you refresh page.