Chrome browser getting ERR_CONNECTION_CLOSED firefox and edge work fine

Added by Philip Dalrymple 10 months ago

In Chrome for a Redmine site that is on port 9292 HTTPS with Apache on 443 to get Lets-Encrypt
returns the following, the main Apache page works fine (no contents but certs are good)

Both Firefox one the same system and Edge on another system work fine but Chrome on two
different systems (one linux one windows) give the below error.

I assume that it is a browser configuration but web search turns up no clue.

This site can’t be reached unexpectedly closed the connection.

Checking the connection
Checking the proxy and the firewall

From the Info page (seen from the same linux system with Firefox)

Redmine version 4.0.4.stable
Ruby version 2.5.5-p157 (2019-03-15) [x86_64-linux]
Rails version 5.2.3
Environment production
Database adapter PostgreSQL
Mailer queue ActiveJob::QueueAdapters::AsyncAdapter
Mailer delivery sendmail
Subversion 1.12.2
Mercurial 4.5.3
Bazaar 2.7.0
Git 2.20.1
Redmine plugins:
redmine_agile 1.4.10
redmine_checklists 3.1.16