Immich behind HTTP/2 reverse proxy supporting extended CONNECT fails to connect WebSocket in web UI at least in Firefox

I have searched the existing issues, both open and closed, to make sure this is not a duplicate report. • Yes The bug There are two ways of WebSocket connection • [HTTP/1.1 via Upgrade: websocket]( • [extended CONNECT for HTTP/2]( [Upgrade: websocket is explicitly disallowed for HTTP/2]( > Note also that HTTP/2 explicitly disallows the use of this mechanism; it is specific to HTTP/1.1. One can check if their reverse proxy supports extended CONNECT for HTTP/2 using e.g. nghttp -nv | grep -F SETTINGS_ENABLE_CONNECT_PROTOCOL Different browsers work with reverse proxies supporting extended CONNECT for HTTP/2 differently. I haven't checked all of them, but so far the newest version of • Chrome instantiates WebSocket connection using HTTP/1.1 via Upgrade: websocket even if the server supports extended CONNECT and even if other, non-WebSocket connections to this server use HTTP/2 or HTTP/3 (I assume because Chrome has not yet implement…