Captive Portal: how to redirect all connections to the portal page?

[myksto]

Hi.
I'm trying to use the captive portal function.
I followed the official guide and everything is ok.
When I connect to the network where the captive portal is bind to and try to connect to any HTTP page I'm immediately redirected to the portal page (where I can insert my credential).
So if I try to connect to "http://www.mysite1.com" I'm redirected to the portal page, I can insert my credential and the I can surf the page and the web.
If I try to connect to any HTTPS site (eg. https://www.mysite2.com") well connection times out with an error and I'm not redirected to the portal page. I can't understand this behaviour as any connection intercepted should be redirected to the portal page.
Am I missing some configuration step?
Is there a way to bypass this and force any type of connections (http and https) to redirect to the portal page?

Thanks a lot.

Michele.