Module skips custom headers

[SkowRon96]

I have prepared a forward proxy as follows:

`http {
log_format main '[$time_local] request="$request" status="$status" bytes="$body_bytes_sent" user="$http_user_agent" request_time="$request_time" x_appname="$http_x_appname" x_appcontext="$http_x_appcontext"';

access_log /var/log/nginx/access-8888.log main;
ignore_invalid_headers on;

server {
listen 8888;
resolver 8.8.8.8 ipv6=off;
proxy_connect;
proxy_connect_allow all;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;

location / {
proxy_pass http://$http_host$request_uri;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
}
}`

When my request is via http, the headers are captured fine:
curl --proxy http://localhost:8888 -H "X-AppName: TEST" http://ipinfo.io/json
2024/12/18 12:18:53 [debug] 15#0: *64 http header: "Host: ipinfo.io"
2024/12/18 12:18:53 [debug] 15#0: *64 http header: "User-Agent: curl/7.68.0"
2024/12/18 12:18:53 [debug] 15#0: *64 http header: "Accept: /"
2024/12/18 12:18:53 [debug] 15#0: *64 http header: "Proxy-Connection: Keep-Alive"
2024/12/18 12:18:53 [debug] 15#0: *64 http header: "X-AppName: TEST"

When my request is via https, headers are not visible:
curl --proxy http://localhost:8888 -H "X-AppName: TEST" https://ipinfo.io/json

2024/12/18 12:19:10 [debug] 15#0: *66 http header: "Host: ipinfo.io:443"
2024/12/18 12:19:10 [debug] 15#0: *66 http header: "User-Agent: curl/7.68.0"
2024/12/18 12:19:10 [debug] 15#0: *66 http header: "Proxy-Connection: Keep-Alive"

What could be the problem? Have I missed any settings or is it a bug in the module itself?