nginx(1.14.2) WebSocket connection to 'wss://xxxx/' failed

[YangHaHabiu]

nginx

nginx version: nginx/1.14.2
built by gcc 4.8.5 20150623 (Red Hat 4.8.5-39) (GCC) 
built with OpenSSL 1.0.2k-fips  26 Jan 2017
TLS SNI support enabled
configure arguments: --user=www --group=www --prefix=/soft/nginx --with-http_stub_status_module --with-http_ssl_module --with-http_realip_module --with-http_gzip_static_module --with-http_v2_module

nginx conf

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}
server {
    listen      443;
    server_name xxxx;
    root /path/to/xxx/public;
    index index.php index.html;

    ssl on;
    ssl_certificate /soft/nginx/ssl/fullchain.cer;
    ssl_certificate_key /soft/nginx/ssl/xxx.key;

    location = /index.php {
        try_files /not_exists @swoole;
    }
    location / {
        try_files $uri $uri/ @swoole;
    }
   location @swoole {
        set $suffix "";

        if ($uri = /index.php) {
            set $suffix ?$query_string;
        }

        proxy_http_version 1.1;
        proxy_set_header Host $http_host;
        proxy_set_header Scheme $scheme;
        proxy_set_header SERVER_PORT $server_port;
        proxy_set_header REMOTE_ADDR $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        # IF https
        proxy_set_header HTTPS "on";

        proxy_pass http://127.0.0.1:1215$suffix;
    }
}

swoole

Swoole => enabled
Author => Swoole Team <team@swoole.com>
Version => 4.5.2
Built => Aug 29 2020 09:48:47
coroutine => enabled
epoll => enabled
eventfd => enabled
signalfd => enabled
cpu_affinity => enabled
spinlock => enabled
rwlock => enabled
openssl => OpenSSL 1.0.2k-fips  26 Jan 2017
http2 => enabled
pcre => enabled
zlib => 1.2.7
mutex_timedlock => enabled
pthread_barrier => enabled
futex => enabled
async_redis => enabled

Directive => Local Value => Master Value
swoole.enable_coroutine => On => On
swoole.enable_library => On => On
swoole.enable_preemptive_scheduler => Off => Off
swoole.display_errors => On => On
swoole.use_shortname => On => On
swoole.unixsock_buffer_size => 8388608 => 8388608

WebSocket connection to 'wss://xxxx/' failed: Error during WebSocket handshake: Unexpected response code: 200