Hi 丨>®@yt3丨,
Yes already on static IP, DNS cache flushed, browser cache also - but still no access to these particular sites. Thx.

Could you maybe tell us what the sites involved are - that might give us some more clues?

Try to ping the domain from the router's [Diagnostics >> Ping Diagnosis].
If no luck there, disable firewall in [Firewall >> General Setup], Data Filter - Disable
Also, check if there are some entries in
Routing >> Static Route
Routing >> Load-Balance/Route Policy
Applications >> LAN DNS / DNS Forwarding
Diagnostics >> DNS Cache Table

Hi ianfretwell
One of them is slingpath.com, which as I say works fine on TP Link router and over cellular data, but can't access through Draytek

Hi 丨>®@yt3丨
Thank you again for the suggestions - answers as follows in red:

Try to ping the domain from the router's [Diagnostics >> Ping Diagnosis]. Shows 100% loss
If no luck there, disable firewall in [Firewall >> General Setup], Data Filter - Disable   Already checked and disabled
Also, check if there are some entries in
Routing >> Static Route  None
Routing >> Load-Balance/Route Policy  All disabled and at factory default
Applications >> LAN DNS / DNS Forwarding  None/empty
Diagnostics >> DNS Cache Table  Empty
 

OK, so that works fine here (2866Lac).

So it does look like your config is stopping it somewhere -

I resolve slingpath to 80.85.87.183 - so does that fall within a range you've got blocked/filtered/redirected anywhere? (and does a client resolve to that same address for you?)

I take it just rebooting the router to factory defaults and then just trying with the bare minimum config isn't an option ?