It sounds to me like one of these things fail
(1) The public IP address of your home network changes because of DSL/whatever reconnects, but this is not reflected in the A record of your DNS entry for the domain. => check dynamic DNS options to reflect changes in the home network public IP address in the DNS record.
(2) There is a problem with port forwarding from your NAT router to your local server. => check the port forwarding, e.g., from your mobile, and see if calling the web site address gets logged in your NGINX access.log
(3) Your local server is not aware of its public DNS name, so it will create URLs that refer to localhost (127.0.0.1). => Check the configuration of your host to handle this properly, or use the proxy_redirect directive to rewrite URLs to respect your public DNS name (https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_redirect).
Cheers,
--j.
(1) The public IP address of your home network changes because of DSL/whatever reconnects, but this is not reflected in the A record of your DNS entry for the domain. => check dynamic DNS options to reflect changes in the home network public IP address in the DNS record.
(2) There is a problem with port forwarding from your NAT router to your local server. => check the port forwarding, e.g., from your mobile, and see if calling the web site address gets logged in your NGINX access.log
(3) Your local server is not aware of its public DNS name, so it will create URLs that refer to localhost (127.0.0.1). => Check the configuration of your host to handle this properly, or use the proxy_redirect directive to rewrite URLs to respect your public DNS name (https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_redirect).
Cheers,
--j.