Okay, so...Ahh progress ..... good job!
I can get to the blue board currently with no problems.
I did a little research on your ISP. They do perform "Traffic Management", but don't appear to do content filtering at source. No-one else seems to be complaining of similar problems with Xplornet.
Have you poked around the Xplornet web portal user profile to see if it has any content filtering options accidently turned on? I'm not a member so I can't check if this feature exists on the portal.
^^-- I don't think it's this, just being redundant in my troubleshooting approach.
More serious suggestion:
1) Sign-up for a VPN service (I use ExpressVPN) and see if the problem goes away. Most providers have a 15 or 30 day free trial. The VPN provider will use their DNS server and their IP addresses.
- This will negate almost any influence Xplornet has as everything will be encrypted and DNS will not be Xplornet's
- It's possible the blue board is blocking your Xplornet IP address for some reason and the VPN will change your IP. To be safe use a CDN or US drop-off site.
If the VPN works, then ask the Xplornet to manually change your IP address and see if that works - just tell them that a few of your favourite sites seemed to have blacklisted you. Most IPs permanently assign you an IP for tracking purposes as required by law (it can change with some ISPs, but they must track the change)
I didn't realize this, but I switch between my own ISP (Rogers) and my Landlords (don't the name). When I'm connect with Rogers, that's when I get that message. When connect with his ISP, no problem.