On 27/04/2021 17:47, Algernon Goss-Custard wrote:
Just in the last couple of weeks I am getting a lot of errors when
trying to access some websites that previously I've not had a problem with.

The error message is "The connection to the server was reset while the
page was loading". In the past when I have occasionally had this message
I could get past it by reloading the page, but now that doesn't help.
The websites are simply not available to me.

Another unrelated problem seems to be to do with something called
Cloudflare. With some websites (not the above ones) I get a message
stating something like "Error 520 Website is returning an unknown error
... Browser working ... Cloudflare working ... Host error". This too has
only arisen in the past couple of weeks.

Anybody got any clues?

If your router is normally left on for months at a time, it is worth
rebooting it. Memory can become clogged - especially if there is a
firmware problem that causes "memory leaks" - and some sites can then
slow sufficiently that they time out and reset. Typically that starts by
needing a second attempt, but can then progress further.