[rt-users] https redirects to http

[CB]

RT 4.0.8

We have set up RT to be accessible over https:
RT_SiteConfig.pm

Set($WebPort, "443");

However when a ticket is resolved or updated, after the Update button is
clicked the website goes to the http site. What configuration option am I
missing?

Have we set up lifecycles incorrectly?

Any suggestions appreciated