Redmine

Hi All

Running 4.1.1 in Alpine container with RAILS_ROOT=/redmine

Apache container as frontend, mod_proxy redirecting "/" to redmine container.

All works fine except for some links rendered incorrectly.
for instance, when opening tickets->ticketnumber->attachment->edit, the rendered link under "Abort" button points to
https://MYDOMAIN/redmine/redmine/issues
instead of
https://MYDOMAIN/redmine/issues
Any idea where that extra /redmine comes from and how to get rid of it? Searching in redmine rb code found no hints.

Thanks
Andrei

Update 2021-02-27
Looks like the corporate reverse proxy is plaing fool here...
In fact, my Apache reverse proxy that's talking to redmine container,
is behind corporate AirLock.
When I talk to the same Apache from the browser on intra net, redmine/redmine does not crawl into back_url in ./app/views/attachments/edit_all.html.erb
<p>
<%= submit_tag l(:button_save) >
<= link_to l(:button_cancel), back_url if back_url.present? %>
</p>

As I have no control over AirLock at intra net perimeter, I'll have to teach my Apache to rewrite the URL.
Haven't touched mod_rewrite since quite a while, can someone suggest a piece of httpd.conf please?

Thanks