BTWholesale Service Information

[#1]

Evening all.
Several times a day, when accessing web pages, I get redirected to a BT error page (See attachment).
I usually have to flush the DNS cache to get everything working again. 
I'm not sure if the issue started when the fibre modem was replaced or if it was happening before or not.  Is anyone else seeing this?  Is it the BT modem, or an actual service problem?
Thanks
-Jim

[#2]

There are a couple of other threads on here with the same issue. The fix is to manually specify the PlusNet DNS servers in the router's settings.
Try these:
Preferred DNS server: 212.159.13.49
Alternate DNS server: 212.159.13.50
(ETA)   These are the DNS servers my router is showing just now - I got the others off a help and support page, so they may be out of date or deprecated.
Primary DNS: 212.159.6.10
Secondary DNS: 212.159.6.9

[#3]

Any pair of those four DNS server addresses can be used. In fact I suspect load balancing makes them all equivalent.