I have installed the application in a server with Tomcat behind an application load balancer redirecting traffic from 8080 to 443. I downloaded the XWiki 11.10.11 version WAR.
However, the https loads kind of broken when modifying configuration in sub-wikis and sends incorrect url for password reset with :80 appended.
This generally means the load balancer is not properly configured and does not forward the port (so Tomcat/XWiki thinks the source URL is using HTTP and not HTTPS).
The general idea is that you need to find how to configure your HTTP proxy so that it calls Tomcat with the source URL provided through the Forwarded HTTP header (or X-Forwarded-* headers for older proxies), you can find more details about this HTTP specification in Forwarded - HTTP | MDN.