I have been experiencing very slow performance from the forums, but not from the web site itself. When the site times out I get a little diagram showing
browser (green) -> cloudflare(green) -> host error
With the aforementioned HTTP 504 error code reported. Which is probably more information than you want to give to end users, but there it is.
Observed on Windows 10/Google Chrome browser. However, the report of HTTP 504 indicates the diagnostics do not believe the client is at fault.
Respectfully,
Brian P.