http3 breaks SSE

[WeidiDeng]

From the community, apparently, SSE doesn't work with http3.

[francislavoie]

/cc @dunglas since Mercure is SSE, do you happen to know how it interacts with HTTP/3?

[dunglas]

At least at protocols level, HTTP/3 works perfectly well with SSE (SSE is just a standard HTTP connection). If there is a bug, it's definitely an implementation bug.

IIRC I already tried the Mercure hub with HTTP/3 and it was working properly.

[mholt]

That's odd. I've asked for a minimal reproducer in the forum thread.