Found the problem:
Discourse seems that it can’t communicate with the S3 server
Message (506 copies reported)
Failed to process hijacked response correctly : Errno::ENETUNREACH : Failed to open TCP connection to 2605:72c0:6fd:b3::b005:1:80 (Network is unreachable - connect(2) for "2605:72c0:6fd:b3::b005:1" port 80)
Backtrace
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1665:in `initialize'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1665:in `open'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1665:in `block in connect'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/timeout-0.4.3/lib/timeout.rb:185:in `block in timeout'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/timeout-0.4.3/lib/timeout.rb:192:in `timeout'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1663:in `connect'
/var/www/discourse/lib/final_destination/http.rb:27:in `block in connect'
/var/www/discourse/lib/final_destination/http.rb:17:in `each'
/var/www/discourse/lib/final_destination/http.rb:17:in `each_with_index'
/var/www/discourse/lib/final_destination/http.rb:17:in `connect'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1642:in `do_start'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1631:in `start'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1070:in `start'
/var/www/discourse/lib/final_destination.rb:544:in `safe_session'
/var/www/discourse/lib/final_destination.rb:479:in `safe_get'
/var/www/discourse/lib/final_destination.rb:170:in `get'
/var/www/discourse/lib/file_helper.rb:91:in `download'
/var/www/discourse/app/controllers/user_avatars_controller.rb:176:in `proxy_avatar'
/var/www/discourse/app/controllers/user_avatars_controller.rb:144:in `show_in_site'
/var/www/discourse/app/controllers/user_avatars_controller.rb:90:in `block (2 levels) in show'
/var/www/discourse/lib/hijack.rb:68:in `instance_eval'
/var/www/discourse/lib/hijack.rb:68:in `block (2 levels) in hijack'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/i18n-1.14.7/lib/i18n.rb:353:in `with_locale'
/var/www/discourse/lib/hijack.rb:68:in `block in hijack'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/concurrent-ruby-1.3.5/lib/concurrent-ruby/concurrent/promises.rb:911:in `callback_on_resolution'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/concurrent-ruby-1.3.5/lib/concurrent-ruby/concurrent/promises.rb:797:in `call_callback'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/concurrent-ruby-1.3.5/lib/concurrent-ruby/concurrent/promises.rb:803:in `call_callbacks'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/concurrent-ruby-1.3.5/lib/concurrent-ruby/concurrent/promises.rb:692:in `resolve_with'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/concurrent-ruby-1.3.5/lib/concurrent-ruby/concurrent/promises.rb:1325:in `resolve'
/var/www/discourse/lib/scheduler/defer.rb:125:in `block in do_work'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:49:in `with_connection'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management.rb:17:in `with_connection'
/var/www/discourse/lib/scheduler/defer.rb:119:in `do_work'
/var/www/discourse/lib/scheduler/defer.rb:105:in `block (2 levels) in start_thread'