another solution may be works for you... first get de ip address of the service you want to block (ej. 216.58.218.142 "youtube"); second create an new service like this and for the final step, you...

you can try block de 443 port, this ports corresponds by default to https protocol, its works, but... this action blocks any https web page...

this model of router dont block any https url, i have the same problem and i dont know how i will doit