I have seen a number of posts in this forum related to random events where a website becomes unreachable or blocked for an unknown reason.  All other sites seem to work fine.

This is an issue I personally experienced after a great deal of troubleshooting.

If you have already:

1. Confirmed that you can access the blocked sites in question from another network (i.e. public wifi)

2. Confirmed that you can access the blocked sites in question by direct connecting your pc/laptop to the cable modem

3. Confirmed from the hosting provider of the web site (happened to me my own web site) that the IP address you are using is not being blocked

4. Confirmed from your ISP that you are not being blocked on outbound traffic to any specific sites

5. Reset the router to factory defaults which did not help

then you will want to either of these options:

1. Clone the Mac address of a computer that is direct attached to the router. This is under the Advanced tab - Network

2. Replace the router.

While this appears to be a workaround - it does work.

I have been unable to confirm with my hosting provider (iPage) that they have a blacklist of hardware Mac Addresses but clearly changing the Mac Address of the router fixed the problem.

As an additional note: Vimeo had blocked me 3 times saying that I was sending erroneous data to the site.  No issues since the Mac clone change.

TP-Link has not confirmed that this is an issue going back several generations of their routers.