Nginx ssl configuration for subdomain -

i have website , multiple subdomains. on each subdomain, except one, use cms generates it's own ssl using let's encrypt. on remaining subdomain want add own certificate cloudflare. generated certificate put in /var/www/my/ now. testing. , in nginx configured block:

server{     listen 443 ssl http2;     listen [::]:443 ssl http2;      ssl_certificate /var/www/my/fullchain.cer;     ssl_certificate_key /var/www/my/my.domain.com.key;     root /var/www/my;      index index.php index.html;      server_name my.domain.com;     location / {          try_files $uri $uri/ =404;     }      location ~ \.php$ {         include /etc/nginx/fastcgi_params;         fastcgi_pass unix:/run/php/php7.0-fpm.sock;         fastcgi_index index.php;         fastcgi_param script_filename /var/www/my/$fastcgi_script_name;     }      location ~ /\.ht {         deny all;     } } 

there seems problem implementation because my.domain.com works else error cloudflare: error 525: ssl handshake failed.

any ideas i'm doing wrong?

thank you

edit:

this conf file cms. how set certificate.

server {     listen 443 ssl http2;     listen [::]:443 ssl http2;      server_name sub.domain.com;     root /var/www/sub/system/nginx-root;      ssl_certificate /home/domain/.acme.sh/sub.domain.com/fullchain.cer;     ssl_certificate_key /home/domain/.acme.sh/sub.domain.com/sub.domain.com.key;     include /var/www/sub/system/files/ssl-params.conf;      location / {         proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;         proxy_set_header x-forwarded-proto $scheme;         proxy_set_header x-real-ip $remote_addr;         proxy_set_header host $http_host;         proxy_pass http://127.0.0.1:2369;      }      location ~ /.well-known {         allow all;     }      client_max_body_size 50m; }