The Sky Sports News HQ is working for me on my smart box with an entertainment & cinema pass.
Maybe try rebooting the nowtv box and perhaps log out and sign back in again to see you can access the channel.
Also double check on the nowtv App under My Account on the box if it shows your active passes when signed into the box.
I’ve just done a factory reset and still wants to charge me. It’s showing my passes are active on my account. I purchased the sports mobile pass today, I wonder if that has something to do with it. I’ve been on chat and they all tell me that I can’t get ssn with entertainment pass. I can watch it on my phone
As far as i am aware you can have an entertainment pass when watching Sky Sports News HQ.
If nowtv have changed their policy (which i don't think they have) then they help guide needs amending about SSN.
I haven't got a sports mobile pass, so maybe like you said it effecting you watching the SSN on your nowtv box with your entertainment & cinema pass.