.deb install of 16.6 on Ubuntu 22.04
After shooting myself in the foot with a CSP, and then relaxing the policy to work, I did some more investigation to get the CSP to work with XWiki, and encountered some other issues.
When through a reverse proxy, the path for resources on the below listed Administration pages is https://host.domain.tld:80/ instead of https://host.domain.tld/ (not specifying port 80)
While these issues are not seen when the reverse proxy (HAProxy) is not used, that the reverse proxy is not performing anything on paths, and that the issue only occurs on some pages, makes me think that this may be an XWiki issue, or an (extremely) unexpected interaction with the reverse proxy on these pages.
As an example of the issue not occurring, on the Rights page under Users & Rights, the path for noavatar.png is https://host.domain.tld/xwiki/bin/skin/resources/icons/xwiki/noavatar.png (without the :80)
HAproxy terminates TLS and forwards (HTTP mode) to the XWiki port of 8080
While configuring the below two settings in xwiki.cfg resolves the issue, it then breaks access to the XWiki instance without the reverse proxy in the path, which I consider to be sub-optimal.
xwiki.home=https://host.domain.tld
xwiki.url.protocol=https
Similar/Same issue on
Pages with the issue
Users & Groups
Users, 31 instances, examples
https://host.domain.tld:80/xwiki/bin/skin/resources/icons/xwiki/noavatar.png
https://host.domain.tld:80/xwiki/resources/icons/silk/text_list_bullets.png
https://host.domain.tld:80/xwiki/resources/icons/silk/arrow_in.png
https://host.domain.tld:80/xwiki/resources/icons/silk/cross.png
https://host.domain.tld:80/xwiki/resources/icons/silk/text_align_justify.png
https://host.domain.tld:80/xwiki/resources/icons/silk/table_sort.png
https://host.domain.tld:80/xwiki/resources/icons/silk/find.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bell.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bin.png
https://host.domain.tld:80/xwiki/resources/icons/silk/control_start.png
https://host.domain.tld:80/xwiki/resources/icons/silk/control_end.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bullet_arrow_down.png
https://host.domain.tld:80/xwiki/resources/icons/silk/arrow_redo.png
Groups, 31 instances, examples same as Users
Invitation, 22 instances, example
https://host.domain.tld:80/xwiki/resources/icons/silk/page_white.png
Look and Feel
Themes, 2 instances, both
https://host.domain.tld:80/xwiki/resources/icons/silk/page_white.png
Content
PDF Export, 1 Instance
https://host.domain.tld:80/xwiki/resources/icons/silk/page_white.png
Editing
WYSIWYG Editor, 1 instance
wss://host.domain.tld:80/xwiki/websocket/xwiki/netflux
Social
Notifications, 64 instances, examples
https://host.domain.tld:80/xwiki/resources/icons/silk/text_list_bullets.png
https://host.domain.tld:80/xwiki/resources/icons/silk/arrow_in.png
https://host.domain.tld:80/xwiki/resources/icons/silk/cross.png
https://host.domain.tld:80/xwiki/resources/icons/silk/text_align_justify.png
https://host.domain.tld:80/xwiki/resources/icons/silk/table_sort.png
https://host.domain.tld:80/xwiki/resources/icons/silk/find.png
https://host.domain.tld:80/xwiki/resources/icons/silk/control_start.png
https://host.domain.tld:80/xwiki/resources/icons/silk/control_end.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bullet_arrow_down.png
https://host.domain.tld:80/xwiki/resources/icons/silk/arrow_redo.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bullet_arrow_up.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bell.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bin.png
Wikis
Wiki Templates, 34 instances, examples
https://host.domain.tld:80/xwiki/resources/icons/silk/text_list_bullets.png
https://host.domain.tld:80/xwiki/resources/icons/silk/arrow_in.png
https://host.domain.tld:80/xwiki/resources/icons/silk/cross.png
https://host.domain.tld:80/xwiki/resources/icons/silk/text_align_justify.png
https://host.domain.tld:80/xwiki/resources/icons/silk/table_sort.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bin.png
https://host.domain.tld:80/xwiki/resources/icons/silk/find.png
https://host.domain.tld:80/xwiki/resources/icons/silk/control_end.png
https://host.domain.tld:80/xwiki/resources/icons/silk/control_start.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bullet_arrow_down.png
https://host.domain.tld:80/xwiki/resources/icons/silk/arrow_redo.png
https://host.domain.tld:80/xwiki/resources/icons/silk/bullet_arrow_up.png
https://host.domain.tld:80/xwiki/resources/icons/silk/user.png