Switching to http3 wrong redirect

[ahmedskh]

I am experiencing an issue where my site fails to load specifically when switching from HTTP/2 to HTTP/3. The initial request over HTTP2 works perfectly, but once the browser switches to HTTP3, Nginx returns a 301 redirect to a malformed URI: "https:///"
this only happens on main page only "adding any path works fine".

Access logs:

"GET / HTTP/3.0" 301 0 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36"

adding fastcgi_param HTTP_HOST $host; works just fine, is this the correct way of fixing it as i have no prior knowledge on this.