Unable to login after install

Hi!

After successful installation, I can't log into the web interface. After trying to login, the page reloads (the username and password are cleared).
Nevertheless, the login to the admin panel is successful. The following was found in the logs  (nginx.log) from the suspicious

2022/06/03 10:06:52 [error] 841517#841517: *33 connect() failed (111: Connection refused) while connecting to upstream, client: 172.16.2.105, server: mail.hexs.local, request: "GET /zx/auth/v2/myself HTTP/2.0", 
upstream: "http://172.16.2.156:8742/zx/auth/v2/myself", host: "mail.hexs.local", referrer: "https://mail.hexs.local/static/login/"                                                                                  
2022/06/03 10:06:52 [error] 841517#841517: *33 connect() failed (111: Connection refused) while connecting to upstream, client: 172.16.2.105, server: mail.hexs.local, request: "GET /zx/login/supported HTTP/2.0",
 upstream: "http://172.16.2.156:8742/zx/login/supported", host: "mail.hexs.local", referrer: "https://mail.hexs.local/static/login/"                                                                                
2022/06/03 10:06:52 [error] 841517#841517: *33 connect() failed (111: Connection refused) while connecting to upstream, client: 172.16.2.105, server: mail.hexs.local, request: "GET /zx/auth/v2/myself HTTP/2.0", 
upstream: "http://172.16.2.156:8742/zx/auth/v2/myself", host: "mail.hexs.local", referrer: "https://mail.hexs.local/static/login/"                                                                                  
2022/06/03 10:06:52 [error] 841517#841517: *33 no live upstreams while connecting to upstream, client: 172.16.2.105, server: mail.hexs.local, request: "GET /zx/auth/v2/myself HTTP/2.0", upstream: "http://zx/zx/a
uth/v2/myself", host: "mail.hexs.local", referrer: "https://mail.hexs.local/static/login/"                                                                                                                          
2022/06/03 10:06:52 [error] 841517#841517: *33 connect() failed (111: Connection refused) while connecting to upstream, client: 172.16.2.105, server: mail.hexs.local, request: "GET /zx/login/supported HTTP/2.0",
 upstream: "http://172.16.2.156:8742/zx/login/supported", host: "mail.hexs.local", referrer: "https://mail.hexs.local/static/login/"                                                                                
2022/06/03 10:06:52 [error] 841517#841517: *33 no live upstreams while connecting to upstream, client: 172.16.2.105, server: mail.hexs.local, request: "GET /zx/login/supported HTTP/2.0", upstream: "http://zx/zx/
login/supported", host: "mail.hexs.local", referrer: "https://mail.hexs.local/static/login/"                                                                                                                        

please tell me what is the reason?