HTTPS handling/inconsistencies

I've purchased my domain name directly from Altervista and have enabled HTTPS, but I get inconsistent handling of the HTTPS. My site seems to only utilize the HTTPS service if the URL uses both HTTPS and WWW in the URL; otherwise it doesn't display SSL verification. Is this the correct handling of the HTTPS service Altervista offers?

Utilizes HTTPS:
https://www.tessisamess.net/
https://www.tessisamess.altervista.org/

Does not utilize HTTPS:
https://tessisamess.net/
https://tessisamess.altervista.org/

Does not forward to HTTPS:
http://www.tessisamess.net/
http://tessisamess.net/
http://www.tessisamess.altervista.org/
http://tessisamess.altervista.org/

Related: Are we allowed to use .htaccess to force correct HTTPS forwarding? When I tried to go that route, the site no longer loaded due to too many redirect attempts.

HTTPS in only supported with "www".

You can force HTTPS with .htaccess, for example:

Code:

---

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^www\.tessisamess\.altervista\.org$
RewriteRule (.*) https://www\.tessisamess\.it/$1 [R=301,L]
RewriteCond %{HTTP_HOST} ^tessisamess\.altervista\.org$
RewriteRule (.*) https://www\.tessisamess\.it/$1 [R=301,L]

---

Let me know if you have any problem.

Bye!

Great, thank you so much for the clarification!