OK, earlier this year, due to PN not giving me a new user deal, which I then got from John Lewis (go figure!) I thought I'd try (again) the Zyxel router that came with it, as it seemed to offer a bit finer control over connected devices (long story)
I updated the firmware.
I did a full reset.
But still I get this weird issue I had earlier this year.
Whilst most http/https traffic is fine, I can browse stuff both wireless and wired, streaming services just lock and fail - again, both wireless and wired.
Locks noticed were -
Wired/Wireless Roku box, Prime
Wire/Wireless Roku Box iPlayer
A restart of the router sorts this.
From my day job (Senior Systems Analyst) I would say that this looks like some sort of memory/resource issue, as if the router is caching or log writing until full, then just stopping on the protocols that streamers use.
I'm leaving it on today and may just start streaming random [-Censored-] (which is what the children do anyway) then see if the other services we have access to fail