login redirect problem

When my users log into the website, they sometimes get redirected to the page they were on (as expected). But most of the time they are redirected to some random page on the site. It seems to be getting more egregious because it is now trying to redirect to subdomains that don't even contain web pages and to http despite the "Force HTTPS" setting being set to "Entire Site".

In my CB login module, the "Login Redirection URL" is blank. I don't have any active redirects in Joomla's Redirect Component. In configuration.php, $live_site is set to ''.

The website is www.3dtravelcompany.com
I have created a test login for you to use so you don't have to go through the registration process, but I don't want to post it "in the open".

The return redirect URL passed to our login module first checks if &return (or if users.login.form.return session data exists) is in the URL they're currently trying to access. This will always be the case for example when accessing a Joomla article they can't access. If it's not we use Joomla API to grab the current menu item they're on if an &Itemid exists in the URL. If it does not we grab the current URL again using Joomla API.

Only thing I can think of is something installed is setting funky URLs for users.login.form.return, but even then we do an isInternal check to make sure domains match. So my next best guess is something installed acting on after login triggers. Are you using CB Auto Actions and if so have you configured any auto actions to act on any login triggers?

The only auto-action that is in use is the reformatting of phone numbers but it's only triggered for onBeforeRegisterFormDisplay and onBeforeUserUpdate.

It's possible there's a 3rd party extension doing it then. Specifically User plugins in Extensions > Plugins or System plugins as both can act on login events. You said it only sometimes does this though. Have you found a way to reliably reproduce the issue? Anything in common when this happens?

I turned off all user plugins (except for Joomla's) with no change in my luck. I tested each menu item on the site (3-4 times each) and there is only 1 page that works as expected ( www.3dtravelcompany.com/about-3d/meet-the-agents ). The rest all redirect to the home page. And once it redirected to a subdomain.

I don't know what else to suggest. Our login redirect URL comes from Joomla API. Does Joomla's login module do this as well? Were you able to reliably reproduce the issue or is it still entirely random?